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diff --git a/csharp/src/Google.Protobuf.Test/Collections/ProtobufEqualityComparersTest.cs b/csharp/src/Google.Protobuf.Test/Collections/ProtobufEqualityComparersTest.cs
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+#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2017 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#endregion
+
+using NUnit.Framework;
+using System.Collections.Generic;
+using System.Linq;
+using static Google.Protobuf.Collections.ProtobufEqualityComparers;
+
+namespace Google.Protobuf.Collections
+{
+    public class ProtobufEqualityComparersTest
+    {
+        private static readonly double[] doubles =
+        {
+            0,
+            1,
+            1.5,
+            -1.5,
+            double.PositiveInfinity,
+            double.NegativeInfinity,
+            // Three different types of NaN...
+            SampleNaNs.Regular,
+            SampleNaNs.SignallingFlipped,
+            SampleNaNs.PayloadFlipped
+        };
+
+        [Test]
+        public void GetEqualityComparer_Default()
+        {
+            // It's more pain than it's worth to try to parameterize these tests.
+            Assert.AreSame(EqualityComparer<object>.Default, GetEqualityComparer<object>());
+            Assert.AreSame(EqualityComparer<string>.Default, GetEqualityComparer<string>());
+            Assert.AreSame(EqualityComparer<int>.Default, GetEqualityComparer<int>());
+            Assert.AreSame(EqualityComparer<int?>.Default, GetEqualityComparer<int?>());
+        }
+
+        [Test]
+        public void GetEqualityComparer_NotDefault()
+        {
+            // It's more pain than it's worth to try to parameterize these tests.
+            Assert.AreSame(BitwiseDoubleEqualityComparer, GetEqualityComparer<double>());
+            Assert.AreSame(BitwiseSingleEqualityComparer, GetEqualityComparer<float>());
+            Assert.AreSame(BitwiseNullableDoubleEqualityComparer, GetEqualityComparer<double?>());
+            Assert.AreSame(BitwiseNullableSingleEqualityComparer, GetEqualityComparer<float?>());
+        }
+
+        [Test]
+        public void DoubleComparisons()
+        {
+            ValidateEqualityComparer(BitwiseDoubleEqualityComparer, doubles);
+        }
+
+        [Test]
+        public void NullableDoubleComparisons()
+        {
+            ValidateEqualityComparer(BitwiseNullableDoubleEqualityComparer, doubles.Select(d => (double?) d).Concat(new double?[] { null }));
+        }
+
+        [Test]
+        public void SingleComparisons()
+        {
+            ValidateEqualityComparer(BitwiseSingleEqualityComparer, doubles.Select(d => (float) d));
+        }
+
+        [Test]
+        public void NullableSingleComparisons()
+        {
+            ValidateEqualityComparer(BitwiseNullableSingleEqualityComparer, doubles.Select(d => (float?) d).Concat(new float?[] { null }));
+        }
+
+        private static void ValidateEqualityComparer<T>(EqualityComparer<T> comparer, IEnumerable<T> values)
+        {
+            var array = values.ToArray();
+            // Each value should be equal to itself, but not to any other value.
+            for (int i = 0; i < array.Length; i++)
+            {
+                for (int j = 0; j < array.Length; j++)
+                {
+                    if (i == j)
+                    {
+                        Assert.IsTrue(comparer.Equals(array[i], array[j]),
+                            "{0} should be equal to itself", array[i], array[j]);
+                    }
+                    else
+                    {
+                        Assert.IsFalse(comparer.Equals(array[i], array[j]),
+                            "{0} and {1} should not be equal", array[i], array[j]);
+                        Assert.AreNotEqual(comparer.GetHashCode(array[i]), comparer.GetHashCode(array[j]),
+                            "Hash codes for {0} and {1} should not be equal", array[i], array[j]);
+                    }
+                }
+            }
+        }
+    }    
+}