public virtual void TestCoreLabelSetWordBehavior()
        {
            CoreLabel foo = new CoreLabel();

            foo.Set(typeof(CoreAnnotations.TextAnnotation), "foo");
            foo.Set(typeof(CoreAnnotations.PartOfSpeechAnnotation), "B");
            foo.Set(typeof(CoreAnnotations.LemmaAnnotation), "fool");
            // Lemma gets removed with word
            ArrayCoreMap copy = new ArrayCoreMap(foo);

            NUnit.Framework.Assert.AreEqual(copy, foo);
            foo.SetWord("foo");
            NUnit.Framework.Assert.AreEqual(copy, foo);
            // same word set
            foo.SetWord("bar");
            NUnit.Framework.Assert.IsFalse(copy.Equals(foo));
            // lemma removed
            foo.SetWord("foo");
            NUnit.Framework.Assert.IsFalse(copy.Equals(foo));
            // still removed
            foo.Set(typeof(CoreAnnotations.LemmaAnnotation), "fool");
            NUnit.Framework.Assert.AreEqual(copy, foo);
            // back to normal
            // Hash code is consistent
            int hashCode = foo.GetHashCode();

            NUnit.Framework.Assert.AreEqual(copy.GetHashCode(), hashCode);
            foo.SetWord("bar");
            NUnit.Framework.Assert.IsFalse(hashCode == foo.GetHashCode());
            foo.SetWord("foo");
            NUnit.Framework.Assert.IsFalse(hashCode == foo.GetHashCode());
            // Hash code doesn't care between a value of null and the key not existing
            NUnit.Framework.Assert.IsTrue(foo.Lemma() == null);
            int lemmalessHashCode = foo.GetHashCode();

            foo.Remove(typeof(CoreAnnotations.LemmaAnnotation));
            NUnit.Framework.Assert.AreEqual(lemmalessHashCode, foo.GetHashCode());
            foo.SetLemma(null);
            NUnit.Framework.Assert.AreEqual(lemmalessHashCode, foo.GetHashCode());
            foo.SetLemma("fool");
            NUnit.Framework.Assert.AreEqual(hashCode, foo.GetHashCode());
            // Check equals
            foo.SetWord("bar");
            foo.SetWord("foo");
            ArrayCoreMap nulledCopy = new ArrayCoreMap(foo);

            NUnit.Framework.Assert.AreEqual(nulledCopy, foo);
            foo.Remove(typeof(CoreAnnotations.LemmaAnnotation));
            NUnit.Framework.Assert.AreEqual(nulledCopy, foo);
        }