remove unused code

src/test/java/com/alibaba/druid/bvt/utils/ConcurrentIdentityHashMapTest.java

@@ -0,0 +1,31 @@
+package com.alibaba.druid.bvt.utils;
+
+import junit.framework.Assert;
+import junit.framework.TestCase;
+
+import com.alibaba.druid.util.ConcurrentIdentityHashMap;
+
+public class ConcurrentIdentityHashMapTest extends TestCase {
+
+    public void test_0() throws Exception {
+        ConcurrentIdentityHashMap<Integer, String> map = new ConcurrentIdentityHashMap<Integer, String>();
+
+        Integer v1 = new Integer(3);
+        map.put(v1, "3");
+
+        Assert.assertTrue(map.contains("3"));
+        Assert.assertTrue(map.containsKey(v1));
+
+        Assert.assertFalse(map.contains("4"));
+        Assert.assertFalse(map.containsKey(new Integer(3)));
+
+        map.put(v1, "33");
+        Assert.assertFalse(map.contains("3"));
+        Assert.assertTrue(map.contains("33"));
+
+        Assert.assertEquals(1, map.size());
+        
+        map.clear();
+        Assert.assertEquals(0, map.size());
+    }
+}