1 files changed, 41 insertions, 0 deletions
diff --git a/impl_core/src/main/java/io/opencensus/implcore/internal/Utils.java b/impl_core/src/main/java/io/opencensus/implcore/internal/Utils.java
new file mode 100644
index 00000000..05a039b9
--- /dev/null
+++ b/impl_core/src/main/java/io/opencensus/implcore/internal/Utils.java
@@ -0,0 +1,41 @@
+/*
+ * 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.internal;
+
+import java.util.List;
+
+/** General internal utility methods. */
+public final class Utils {
+
+  private Utils() {}
+
+  /**
+   * Throws a {@link NullPointerException} if any of the list elements is null.
+   *
+   * @param list the argument list to check for null.
+   * @param errorMessage the message to use for the exception. Will be converted to a string using
+   *     {@link String#valueOf(Object)}.
+   */
+  public static <T> void checkListElementNotNull(
+      List<T> list, @javax.annotation.Nullable Object errorMessage) {
+    for (T element : list) {
+      if (element == null) {
+        throw new NullPointerException(String.valueOf(errorMessage));
+      }
+    }
+  }
+}