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diff --git a/src/main/java/org/apache/commons/math3/util/DefaultTransformer.java b/src/main/java/org/apache/commons/math3/util/DefaultTransformer.java
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+++ b/src/main/java/org/apache/commons/math3/util/DefaultTransformer.java
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+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 org.apache.commons.math3.util;
+
+import org.apache.commons.math3.exception.MathIllegalArgumentException;
+import org.apache.commons.math3.exception.NullArgumentException;
+import org.apache.commons.math3.exception.util.LocalizedFormats;
+
+import java.io.Serializable;
+
+/**
+ * A Default NumberTransformer for java.lang.Numbers and Numeric Strings. This provides some simple
+ * conversion capabilities to turn any java.lang.Number into a primitive double or to turn a String
+ * representation of a Number into a double.
+ */
+public class DefaultTransformer implements NumberTransformer, Serializable {
+
+    /** Serializable version identifier */
+    private static final long serialVersionUID = 4019938025047800455L;
+
+    /**
+     * @param o the object that gets transformed.
+     * @return a double primitive representation of the Object o.
+     * @throws NullArgumentException if Object <code>o</code> is {@code null}.
+     * @throws MathIllegalArgumentException if Object <code>o</code> cannot successfully be
+     *     transformed
+     * @see <a
+     *     href="http://commons.apache.org/collections/api-release/org/apache/commons/collections/Transformer.html">Commons
+     *     Collections Transformer</a>
+     */
+    public double transform(Object o) throws NullArgumentException, MathIllegalArgumentException {
+
+        if (o == null) {
+            throw new NullArgumentException(LocalizedFormats.OBJECT_TRANSFORMATION);
+        }
+
+        if (o instanceof Number) {
+            return ((Number) o).doubleValue();
+        }
+
+        try {
+            return Double.parseDouble(o.toString());
+        } catch (NumberFormatException e) {
+            throw new MathIllegalArgumentException(
+                    LocalizedFormats.CANNOT_TRANSFORM_TO_DOUBLE, o.toString());
+        }
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public boolean equals(Object other) {
+        if (this == other) {
+            return true;
+        }
+        return other instanceof DefaultTransformer;
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public int hashCode() {
+        // some arbitrary number ...
+        return 401993047;
+    }
+}