Added Change utility class for representing change events + Moved Match class to org.onlab.util

Change-Id: I08e8cd8dd92983bd2764e83016b1abc0bf29388f
diff --git a/utils/misc/src/test/java/org/onlab/util/MatchTest.java b/utils/misc/src/test/java/org/onlab/util/MatchTest.java
new file mode 100644
index 0000000..d0b1b78
--- /dev/null
+++ b/utils/misc/src/test/java/org/onlab/util/MatchTest.java
@@ -0,0 +1,67 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * 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 org.onlab.util;
+
+import static junit.framework.TestCase.assertEquals;
+import static junit.framework.TestCase.assertFalse;
+import static junit.framework.TestCase.assertTrue;
+
+import org.junit.Test;
+
+import com.google.common.base.Objects;
+
+/**
+ * Unit tests for Match.
+ */
+public class MatchTest {
+
+    @Test
+    public void testMatches() {
+        Match<String> m1 = Match.any();
+        assertTrue(m1.matches(null));
+        assertTrue(m1.matches("foo"));
+        assertTrue(m1.matches("bar"));
+
+        Match<String> m2 = Match.ifNull();
+        assertTrue(m2.matches(null));
+        assertFalse(m2.matches("foo"));
+
+        Match<String> m3 = Match.ifValue("foo");
+        assertFalse(m3.matches(null));
+        assertFalse(m3.matches("bar"));
+        assertTrue(m3.matches("foo"));
+    }
+
+    @Test
+    public void testEquals() {
+        Match<String> m1 = Match.any();
+        Match<String> m2 = Match.any();
+        Match<String> m3 = Match.ifNull();
+        Match<String> m4 = Match.ifValue("bar");
+        assertEquals(m1, m2);
+        assertFalse(Objects.equal(m1, m3));
+        assertFalse(Objects.equal(m3, m4));
+    }
+
+    @Test
+    public void testMap() {
+        Match<String> m1 = Match.ifNull();
+        assertEquals(m1.map(s -> "bar"), Match.ifNull());
+        Match<String> m2 = Match.ifValue("foo");
+        Match<String> m3 = m2.map(s -> "bar");
+        assertTrue(m3.matches("bar"));
+    }
+}