Remove Old Gauge and correct exception messages (#1502)

15 files changed, 35 insertions, 252 deletions

diff --git a/api/src/main/java/io/opencensus/metrics/DoubleGauge.java b/api/src/main/java/io/opencensus/metrics/DoubleGauge.java
index 62730a06..de2b053b 100644
--- a/api/src/main/java/io/opencensus/metrics/DoubleGauge.java
+++ b/api/src/main/java/io/opencensus/metrics/DoubleGauge.java
@@ -172,15 +172,15 @@ public abstract class DoubleGauge {
       Utils.checkNotNull(name, "name");
       Utils.checkNotNull(description, "description");
       Utils.checkNotNull(unit, "unit");
-      Utils.checkNotNull(labelKeys, "labelKeys should not be null.");
-      Utils.checkListElementNotNull(labelKeys, "labelKeys element should not be null.");
+      Utils.checkListElementNotNull(
+          Utils.checkNotNull(labelKeys, "labelKeys"), "labelKey element should not be null.");
       labelKeysSize = labelKeys.size();
     }
 
     @Override
     public NoopDoublePoint getOrCreateTimeSeries(List<LabelValue> labelValues) {
-      Utils.checkNotNull(labelValues, "labelValues should not be null.");
-      Utils.checkListElementNotNull(labelValues, "labelValues element should not be null.");
+      Utils.checkListElementNotNull(
+          Utils.checkNotNull(labelValues, "labelValues"), "labelValue element should not be null.");
       Utils.checkArgument(labelKeysSize == labelValues.size(), "Incorrect number of labels.");
       return NoopDoublePoint.INSTANCE;
     }
@@ -192,7 +192,7 @@ public abstract class DoubleGauge {
 
     @Override
     public void removeTimeSeries(List<LabelValue> labelValues) {
-      Utils.checkNotNull(labelValues, "labelValues should not be null.");
+      Utils.checkNotNull(labelValues, "labelValues");
     }
 
     @Override
diff --git a/api/src/main/java/io/opencensus/metrics/LongGauge.java b/api/src/main/java/io/opencensus/metrics/LongGauge.java
index f473a8ac..8ca760be 100644
--- a/api/src/main/java/io/opencensus/metrics/LongGauge.java
+++ b/api/src/main/java/io/opencensus/metrics/LongGauge.java
@@ -171,8 +171,8 @@ public abstract class LongGauge {
 
     @Override
     public NoopLongPoint getOrCreateTimeSeries(List<LabelValue> labelValues) {
-      Utils.checkNotNull(labelValues, "labelValues should not be null.");
-      Utils.checkListElementNotNull(labelValues, "labelValues element should not be null.");
+      Utils.checkListElementNotNull(
+          Utils.checkNotNull(labelValues, "labelValues"), "labelValue element should not be null.");
       Utils.checkArgument(labelKeysSize == labelValues.size(), "Incorrect number of labels.");
       return NoopLongPoint.INSTANCE;
     }
@@ -184,7 +184,7 @@ public abstract class LongGauge {
 
     @Override
     public void removeTimeSeries(List<LabelValue> labelValues) {
-      Utils.checkNotNull(labelValues, "labelValues should not be null.");
+      Utils.checkNotNull(labelValues, "labelValues");
     }
 
     @Override
diff --git a/api/src/main/java/io/opencensus/stats/Aggregation.java b/api/src/main/java/io/opencensus/stats/Aggregation.java
index f5efed9b..9c95e847 100644
--- a/api/src/main/java/io/opencensus/stats/Aggregation.java
+++ b/api/src/main/java/io/opencensus/stats/Aggregation.java
@@ -180,7 +180,7 @@ public abstract class Aggregation {
      * @since 0.8
      */
     public static Distribution create(BucketBoundaries bucketBoundaries) {
-      Utils.checkNotNull(bucketBoundaries, "bucketBoundaries should not be null.");
+      Utils.checkNotNull(bucketBoundaries, "bucketBoundaries");
       return new AutoValue_Aggregation_Distribution(bucketBoundaries);
     }
 
diff --git a/api/src/main/java/io/opencensus/stats/AggregationData.java b/api/src/main/java/io/opencensus/stats/AggregationData.java
index eb7d40b3..c6e12b67 100644
--- a/api/src/main/java/io/opencensus/stats/AggregationData.java
+++ b/api/src/main/java/io/opencensus/stats/AggregationData.java
@@ -288,15 +288,15 @@ public abstract class AggregationData {
         Utils.checkArgument(min <= max, "max should be greater or equal to min.");
       }
 
-      Utils.checkNotNull(bucketCounts, "bucket counts should not be null.");
+      Utils.checkNotNull(bucketCounts, "bucketCounts");
       List<Long> bucketCountsCopy = Collections.unmodifiableList(new ArrayList<Long>(bucketCounts));
       for (Long bucket : bucketCountsCopy) {
-        Utils.checkNotNull(bucket, "bucket should not be null.");
+        Utils.checkNotNull(bucket, "bucket");
       }
 
       Utils.checkNotNull(exemplars, "exemplar list should not be null.");
       for (Exemplar exemplar : exemplars) {
-        Utils.checkNotNull(exemplar, "exemplar should not be null.");
+        Utils.checkNotNull(exemplar, "exemplar");
       }
 
       return new AutoValue_AggregationData_DistributionData(
diff --git a/api/src/main/java/io/opencensus/stats/BucketBoundaries.java b/api/src/main/java/io/opencensus/stats/BucketBoundaries.java
index 573a9e10..61e21e6c 100644
--- a/api/src/main/java/io/opencensus/stats/BucketBoundaries.java
+++ b/api/src/main/java/io/opencensus/stats/BucketBoundaries.java
@@ -42,7 +42,7 @@ public abstract class BucketBoundaries {
    * @since 0.8
    */
   public static final BucketBoundaries create(List<Double> bucketBoundaries) {
-    Utils.checkNotNull(bucketBoundaries, "bucketBoundaries list should not be null.");
+    Utils.checkNotNull(bucketBoundaries, "bucketBoundaries");
     List<Double> bucketBoundariesCopy = new ArrayList<Double>(bucketBoundaries); // Deep copy.
     // Check if sorted.
     if (bucketBoundariesCopy.size() > 1) {
diff --git a/api/src/test/java/io/opencensus/metrics/DoubleGaugeTest.java b/api/src/test/java/io/opencensus/metrics/DoubleGaugeTest.java
index 5690bd44..b0cdea7c 100644
--- a/api/src/test/java/io/opencensus/metrics/DoubleGaugeTest.java
+++ b/api/src/test/java/io/opencensus/metrics/DoubleGaugeTest.java
@@ -49,7 +49,7 @@ public class DoubleGaugeTest {
     DoubleGauge doubleGauge =
         DoubleGauge.newNoopDoubleGauge(NAME, DESCRIPTION, UNIT, EMPTY_LABEL_KEYS);
     thrown.expect(NullPointerException.class);
-    thrown.expectMessage("labelValues should not be null.");
+    thrown.expectMessage("labelValues");
     doubleGauge.getOrCreateTimeSeries(null);
   }
 
@@ -58,7 +58,7 @@ public class DoubleGaugeTest {
     List<LabelValue> labelValues = Collections.singletonList(null);
     DoubleGauge doubleGauge = DoubleGauge.newNoopDoubleGauge(NAME, DESCRIPTION, UNIT, LABEL_KEY);
     thrown.expect(NullPointerException.class);
-    thrown.expectMessage("labelValues element should not be null.");
+    thrown.expectMessage("labelValue element should not be null.");
     doubleGauge.getOrCreateTimeSeries(labelValues);
   }
 
@@ -74,7 +74,7 @@ public class DoubleGaugeTest {
   public void noopRemoveTimeSeries_WithNullLabelValues() {
     DoubleGauge doubleGauge = DoubleGauge.newNoopDoubleGauge(NAME, DESCRIPTION, UNIT, LABEL_KEY);
     thrown.expect(NullPointerException.class);
-    thrown.expectMessage("labelValues should not be null.");
+    thrown.expectMessage("labelValues");
     doubleGauge.removeTimeSeries(null);
   }
 
diff --git a/api/src/test/java/io/opencensus/metrics/LongGaugeTest.java b/api/src/test/java/io/opencensus/metrics/LongGaugeTest.java
index 768abe06..eedb287c 100644
--- a/api/src/test/java/io/opencensus/metrics/LongGaugeTest.java
+++ b/api/src/test/java/io/opencensus/metrics/LongGaugeTest.java
@@ -48,7 +48,7 @@ public class LongGaugeTest {
   public void noopGetOrCreateTimeSeries_WithNullLabelValues() {
     LongGauge longGauge = LongGauge.newNoopLongGauge(NAME, DESCRIPTION, UNIT, EMPTY_LABEL_KEYS);
     thrown.expect(NullPointerException.class);
-    thrown.expectMessage("labelValues should not be null.");
+    thrown.expectMessage("labelValues");
     longGauge.getOrCreateTimeSeries(null);
   }
 
@@ -57,7 +57,7 @@ public class LongGaugeTest {
     List<LabelValue> labelValues = Collections.singletonList(null);
     LongGauge longGauge = LongGauge.newNoopLongGauge(NAME, DESCRIPTION, UNIT, LABEL_KEY);
     thrown.expect(NullPointerException.class);
-    thrown.expectMessage("labelValues element should not be null.");
+    thrown.expectMessage("labelValue element should not be null.");
     longGauge.getOrCreateTimeSeries(labelValues);
   }
 
@@ -73,7 +73,7 @@ public class LongGaugeTest {
   public void noopRemoveTimeSeries_WithNullLabelValues() {
     LongGauge longGauge = LongGauge.newNoopLongGauge(NAME, DESCRIPTION, UNIT, LABEL_KEY);
     thrown.expect(NullPointerException.class);
-    thrown.expectMessage("labelValues should not be null.");
+    thrown.expectMessage("labelValues");
     longGauge.removeTimeSeries(null);
   }
 
diff --git a/api/src/test/java/io/opencensus/stats/AggregationDataTest.java b/api/src/test/java/io/opencensus/stats/AggregationDataTest.java
index 60551600..a6d6d1de 100644
--- a/api/src/test/java/io/opencensus/stats/AggregationDataTest.java
+++ b/api/src/test/java/io/opencensus/stats/AggregationDataTest.java
@@ -108,14 +108,14 @@ public class AggregationDataTest {
   @Test
   public void preventNullBucketCountList() {
     thrown.expect(NullPointerException.class);
-    thrown.expectMessage("bucket counts should not be null.");
+    thrown.expectMessage("bucketCounts");
     DistributionData.create(1, 1, 1, 1, 0, null);
   }
 
   @Test
   public void preventNullBucket() {
     thrown.expect(NullPointerException.class);
-    thrown.expectMessage("bucket should not be null.");
+    thrown.expectMessage("bucket");
     DistributionData.create(1, 1, 1, 1, 0, Arrays.asList(0L, 1L, null));
   }
 
@@ -129,7 +129,7 @@ public class AggregationDataTest {
   @Test
   public void preventNullExemplar() {
     thrown.expect(NullPointerException.class);
-    thrown.expectMessage("exemplar should not be null.");
+    thrown.expectMessage("exemplar");
     DistributionData.create(
         1, 1, 1, 1, 0, Arrays.asList(0L, 1L, 1L), Collections.<Exemplar>singletonList(null));
   }
diff --git a/api/src/test/java/io/opencensus/stats/AggregationTest.java b/api/src/test/java/io/opencensus/stats/AggregationTest.java
index c2e6a716..cf337030 100644
--- a/api/src/test/java/io/opencensus/stats/AggregationTest.java
+++ b/api/src/test/java/io/opencensus/stats/AggregationTest.java
@@ -50,7 +50,7 @@ public class AggregationTest {
   @Test
   public void testNullBucketBoundaries() {
     thrown.expect(NullPointerException.class);
-    thrown.expectMessage("bucketBoundaries should not be null.");
+    thrown.expectMessage("bucketBoundaries");
     Distribution.create(null);
   }
 
diff --git a/impl_core/src/main/java/io/opencensus/implcore/metrics/DoubleGaugeImpl.java b/impl_core/src/main/java/io/opencensus/implcore/metrics/DoubleGaugeImpl.java
index d329091e..86b3512d 100644
--- a/impl_core/src/main/java/io/opencensus/implcore/metrics/DoubleGaugeImpl.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/metrics/DoubleGaugeImpl.java
@@ -70,8 +70,7 @@ public final class DoubleGaugeImpl extends DoubleGauge implements Meter {
 
     List<LabelValue> labelValuesCopy =
         Collections.unmodifiableList(
-            new ArrayList<LabelValue>(
-                checkNotNull(labelValues, "labelValues should not be null.")));
+            new ArrayList<LabelValue>(checkNotNull(labelValues, "labelValues")));
     return registerTimeSeries(labelValuesCopy);
   }
 
@@ -87,7 +86,7 @@ public final class DoubleGaugeImpl extends DoubleGauge implements Meter {
 
   @Override
   public synchronized void removeTimeSeries(List<LabelValue> labelValues) {
-    checkNotNull(labelValues, "labelValues should not be null.");
+    checkNotNull(labelValues, "labelValues");
 
     Map<List<LabelValue>, PointImpl> registeredPointsCopy =
         new LinkedHashMap<List<LabelValue>, PointImpl>(registeredPoints);
@@ -112,7 +111,7 @@ public final class DoubleGaugeImpl extends DoubleGauge implements Meter {
     }
 
     checkArgument(labelKeysSize == labelValues.size(), "Incorrect number of labels.");
-    Utils.checkListElementNotNull(labelValues, "labelValues element should not be null.");
+    Utils.checkListElementNotNull(labelValues, "labelValue element should not be null.");
 
     PointImpl newPoint = new PointImpl(labelValues);
     // Updating the map of points happens under a lock to avoid multiple add operations
diff --git a/impl_core/src/main/java/io/opencensus/implcore/metrics/Gauge.java b/impl_core/src/main/java/io/opencensus/implcore/metrics/Gauge.java
deleted file mode 100644
index e52fcff5..00000000
--- a/impl_core/src/main/java/io/opencensus/implcore/metrics/Gauge.java
+++ /dev/null
@@ -1,109 +0,0 @@
-/*
- * Copyright 2018, OpenCensus Authors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package io.opencensus.implcore.metrics;
-
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import io.opencensus.common.Clock;
-import io.opencensus.common.ToDoubleFunction;
-import io.opencensus.common.ToLongFunction;
-import io.opencensus.metrics.LabelKey;
-import io.opencensus.metrics.LabelValue;
-import io.opencensus.metrics.export.Metric;
-import io.opencensus.metrics.export.MetricDescriptor;
-import io.opencensus.metrics.export.MetricDescriptor.Type;
-import io.opencensus.metrics.export.Point;
-import io.opencensus.metrics.export.TimeSeries;
-import io.opencensus.metrics.export.Value;
-import java.util.Collections;
-import java.util.List;
-
-abstract class Gauge {
-  private final MetricDescriptor metricDescriptor;
-  private final List<LabelValue> labelValues;
-
-  final Metric getMetric(Clock clock) {
-    return Metric.createWithOneTimeSeries(metricDescriptor, getTimeSeries(clock));
-  }
-
-  abstract TimeSeries getTimeSeries(Clock clock);
-
-  static final class DoubleGauge<T> extends Gauge {
-    private final T obj;
-    private final ToDoubleFunction<T> function;
-
-    DoubleGauge(
-        String name,
-        String description,
-        String unit,
-        List<LabelKey> labelKeys,
-        List<LabelValue> labelValues,
-        T obj,
-        ToDoubleFunction<T> function) {
-      super(
-          MetricDescriptor.create(name, description, unit, Type.GAUGE_DOUBLE, labelKeys),
-          labelValues);
-      this.obj = obj;
-      this.function = function;
-    }
-
-    @Override
-    TimeSeries getTimeSeries(Clock clock) {
-      return TimeSeries.createWithOnePoint(
-          getLabelValues(),
-          Point.create(Value.doubleValue(function.applyAsDouble(obj)), clock.now()),
-          null);
-    }
-  }
-
-  static final class LongGauge<T> extends Gauge {
-    private final T obj;
-    private final ToLongFunction<T> function;
-
-    LongGauge(
-        String name,
-        String description,
-        String unit,
-        List<LabelKey> labelKeys,
-        List<LabelValue> labelValues,
-        T obj,
-        ToLongFunction<T> function) {
-      super(
-          MetricDescriptor.create(name, description, unit, Type.GAUGE_INT64, labelKeys),
-          labelValues);
-      this.obj = obj;
-      this.function = function;
-    }
-
-    @Override
-    TimeSeries getTimeSeries(Clock clock) {
-      return TimeSeries.createWithOnePoint(
-          getLabelValues(),
-          Point.create(Value.longValue(function.applyAsLong(obj)), clock.now()),
-          null);
-    }
-  }
-
-  List<LabelValue> getLabelValues() {
-    return labelValues;
-  }
-
-  Gauge(MetricDescriptor metricDescriptor, List<LabelValue> labelValues) {
-    this.metricDescriptor = checkNotNull(metricDescriptor, "metricDescriptor");
-    this.labelValues = Collections.unmodifiableList(labelValues);
-  }
-}
diff --git a/impl_core/src/main/java/io/opencensus/implcore/metrics/LongGaugeImpl.java b/impl_core/src/main/java/io/opencensus/implcore/metrics/LongGaugeImpl.java
index 64cb3200..f158e656 100644
--- a/impl_core/src/main/java/io/opencensus/implcore/metrics/LongGaugeImpl.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/metrics/LongGaugeImpl.java
@@ -70,8 +70,7 @@ public final class LongGaugeImpl extends LongGauge implements Meter {
 
     List<LabelValue> labelValuesCopy =
         Collections.unmodifiableList(
-            new ArrayList<LabelValue>(
-                checkNotNull(labelValues, "labelValues should not be null.")));
+            new ArrayList<LabelValue>(checkNotNull(labelValues, "labelValues")));
     return registerTimeSeries(labelValuesCopy);
   }
 
@@ -87,7 +86,7 @@ public final class LongGaugeImpl extends LongGauge implements Meter {
 
   @Override
   public synchronized void removeTimeSeries(List<LabelValue> labelValues) {
-    checkNotNull(labelValues, "labelValues should not be null.");
+    checkNotNull(labelValues, "labelValues");
 
     Map<List<LabelValue>, PointImpl> registeredPointsCopy =
         new LinkedHashMap<List<LabelValue>, PointImpl>(registeredPoints);
@@ -112,7 +111,7 @@ public final class LongGaugeImpl extends LongGauge implements Meter {
     }
 
     checkArgument(labelKeysSize == labelValues.size(), "Incorrect number of labels.");
-    Utils.checkListElementNotNull(labelValues, "labelValues element should not be null.");
+    Utils.checkListElementNotNull(labelValues, "labelValue element should not be null.");
 
     PointImpl newPoint = new PointImpl(labelValues);
     // Updating the map of points happens under a lock to avoid multiple add operations
diff --git a/impl_core/src/test/java/io/opencensus/implcore/metrics/DoubleGaugeImplTest.java b/impl_core/src/test/java/io/opencensus/implcore/metrics/DoubleGaugeImplTest.java
index 61de77b6..b0899084 100644
--- a/impl_core/src/test/java/io/opencensus/implcore/metrics/DoubleGaugeImplTest.java
+++ b/impl_core/src/test/java/io/opencensus/implcore/metrics/DoubleGaugeImplTest.java
@@ -69,7 +69,7 @@ public class DoubleGaugeImplTest {
   @Test
   public void getOrCreateTimeSeries_WithNullLabelValues() {
     thrown.expect(NullPointerException.class);
-    thrown.expectMessage("labelValues should not be null.");
+    thrown.expectMessage("labelValues");
     doubleGauge.getOrCreateTimeSeries(null);
   }
 
@@ -82,7 +82,7 @@ public class DoubleGaugeImplTest {
     DoubleGaugeImpl doubleGauge =
         new DoubleGaugeImpl(METRIC_NAME, METRIC_DESCRIPTION, METRIC_UNIT, labelKeys);
     thrown.expect(NullPointerException.class);
-    thrown.expectMessage("labelValues element should not be null.");
+    thrown.expectMessage("labelValue element should not be null.");
     doubleGauge.getOrCreateTimeSeries(labelValues);
   }
 
@@ -174,7 +174,7 @@ public class DoubleGaugeImplTest {
   @Test
   public void removeTimeSeries_WithNullLabelValues() {
     thrown.expect(NullPointerException.class);
-    thrown.expectMessage("labelValues should not be null.");
+    thrown.expectMessage("labelValues");
     doubleGauge.removeTimeSeries(null);
   }
 
diff --git a/impl_core/src/test/java/io/opencensus/implcore/metrics/GaugeTest.java b/impl_core/src/test/java/io/opencensus/implcore/metrics/GaugeTest.java
deleted file mode 100644
index 4c4c3a92..00000000
--- a/impl_core/src/test/java/io/opencensus/implcore/metrics/GaugeTest.java
+++ /dev/null
@@ -1,106 +0,0 @@
-/*
- * Copyright 2018, OpenCensus Authors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package io.opencensus.implcore.metrics;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import io.opencensus.common.Timestamp;
-import io.opencensus.common.ToDoubleFunction;
-import io.opencensus.common.ToLongFunction;
-import io.opencensus.implcore.metrics.Gauge.DoubleGauge;
-import io.opencensus.implcore.metrics.Gauge.LongGauge;
-import io.opencensus.metrics.LabelKey;
-import io.opencensus.metrics.LabelValue;
-import io.opencensus.metrics.export.Metric;
-import io.opencensus.metrics.export.MetricDescriptor;
-import io.opencensus.metrics.export.MetricDescriptor.Type;
-import io.opencensus.metrics.export.Point;
-import io.opencensus.metrics.export.TimeSeries;
-import io.opencensus.metrics.export.Value;
-import io.opencensus.testing.common.TestClock;
-import java.util.Collections;
-import java.util.List;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-
-/** Unit tests for {@link Gauge}. */
-@RunWith(JUnit4.class)
-public class GaugeTest {
-  private static final String NAME = "name";
-  private static final String DESCRIPTION = "description";
-  private static final String UNIT = "1";
-  private static final List<LabelKey> LABEL_KEYS =
-      Collections.unmodifiableList(
-          Collections.singletonList(LabelKey.create("key", "key description")));
-  private static final List<LabelValue> LABEL_VALUES =
-      Collections.unmodifiableList(Collections.singletonList(LabelValue.create("value")));
-  private static final Object OBJ = new Object();
-  private static final Timestamp TEST_TIME = Timestamp.create(1234, 123);
-
-  private final Gauge longGauge =
-      new LongGauge<Object>(
-          NAME,
-          DESCRIPTION,
-          UNIT,
-          LABEL_KEYS,
-          LABEL_VALUES,
-          OBJ,
-          new ToLongFunction<Object>() {
-            @Override
-            public long applyAsLong(Object value) {
-              return value.hashCode();
-            }
-          });
-  private final Gauge doubleGauge =
-      new DoubleGauge<Object>(
-          NAME,
-          DESCRIPTION,
-          UNIT,
-          LABEL_KEYS,
-          LABEL_VALUES,
-          OBJ,
-          new ToDoubleFunction<Object>() {
-            @Override
-            public double applyAsDouble(Object value) {
-              return value.hashCode();
-            }
-          });
-  private final TestClock testClock = TestClock.create(TEST_TIME);
-
-  @Test
-  public void longGauge_GetMetric() {
-    assertThat(longGauge.getMetric(testClock))
-        .isEqualTo(
-            Metric.createWithOneTimeSeries(
-                MetricDescriptor.create(NAME, DESCRIPTION, UNIT, Type.GAUGE_INT64, LABEL_KEYS),
-                TimeSeries.createWithOnePoint(
-                    LABEL_VALUES, Point.create(Value.longValue(OBJ.hashCode()), TEST_TIME), null)));
-  }
-
-  @Test
-  public void doubleGauge_GetMetric() {
-    assertThat(doubleGauge.getMetric(testClock))
-        .isEqualTo(
-            Metric.createWithOneTimeSeries(
-                MetricDescriptor.create(NAME, DESCRIPTION, UNIT, Type.GAUGE_DOUBLE, LABEL_KEYS),
-                TimeSeries.createWithOnePoint(
-                    LABEL_VALUES,
-                    Point.create(Value.doubleValue(OBJ.hashCode()), TEST_TIME),
-                    null)));
-  }
-}
diff --git a/impl_core/src/test/java/io/opencensus/implcore/metrics/LongGaugeImplTest.java b/impl_core/src/test/java/io/opencensus/implcore/metrics/LongGaugeImplTest.java
index 25797cff..e83bb642 100644
--- a/impl_core/src/test/java/io/opencensus/implcore/metrics/LongGaugeImplTest.java
+++ b/impl_core/src/test/java/io/opencensus/implcore/metrics/LongGaugeImplTest.java
@@ -69,7 +69,7 @@ public class LongGaugeImplTest {
   @Test
   public void getOrCreateTimeSeries_WithNullLabelValues() {
     thrown.expect(NullPointerException.class);
-    thrown.expectMessage("labelValues should not be null.");
+    thrown.expectMessage("labelValues");
     longGaugeMetric.getOrCreateTimeSeries(null);
   }
 
@@ -82,7 +82,7 @@ public class LongGaugeImplTest {
     LongGaugeImpl longGauge =
         new LongGaugeImpl(METRIC_NAME, METRIC_DESCRIPTION, METRIC_UNIT, labelKeys);
     thrown.expect(NullPointerException.class);
-    thrown.expectMessage("labelValues element should not be null.");
+    thrown.expectMessage("labelValue element should not be null.");
     longGauge.getOrCreateTimeSeries(labelValues);
   }
 
@@ -169,7 +169,7 @@ public class LongGaugeImplTest {
   @Test
   public void removeTimeSeries_WithNullLabelValues() {
     thrown.expect(NullPointerException.class);
-    thrown.expectMessage("labelValues should not be null.");
+    thrown.expectMessage("labelValues");
     longGaugeMetric.removeTimeSeries(null);
   }