diff --git a/icu4j/src/com/ibm/icu/dev/test/util/TestUtilities.java b/icu4j/src/com/ibm/icu/dev/test/util/TestUtilities.java
index d7f32b1b023..ce69cd987a6 100644
--- a/icu4j/src/com/ibm/icu/dev/test/util/TestUtilities.java
+++ b/icu4j/src/com/ibm/icu/dev/test/util/TestUtilities.java
@@ -24,6 +24,7 @@ import java.util.TreeSet;
 
 import com.ibm.icu.dev.test.TestBoilerplate;
 import com.ibm.icu.dev.test.TestFmwk;
+import com.ibm.icu.impl.CollectionUtilities;
 import com.ibm.icu.impl.Utility;
 import com.ibm.icu.lang.UCharacter;
 import com.ibm.icu.lang.UProperty;
diff --git a/icu4j/src/com/ibm/icu/dev/test/util/UnicodeMap.java b/icu4j/src/com/ibm/icu/dev/test/util/UnicodeMap.java
index 7ec67463b77..da746caebd3 100644
--- a/icu4j/src/com/ibm/icu/dev/test/util/UnicodeMap.java
+++ b/icu4j/src/com/ibm/icu/dev/test/util/UnicodeMap.java
@@ -48,16 +48,33 @@ public final class UnicodeMap implements Cloneable, Freezable, Externalizable {
     static final long GROWTH_PERCENT = 200; // 100 is no growth!
     static final long GROWTH_GAP = 10; // extra bump!
 
-    private int length = 2;
-    private int[] transitions = {0,0x110000,0,0,0,0,0,0,0,0};
-    private Object[] values = new Object[10];
+    private int length;
+    // two parallel arrays to save memory. Wish Java had structs.
+    private int[] transitions;
+    private Object[] values;
     
     private LinkedHashSet availableValues = new LinkedHashSet();
-    private transient boolean staleAvailableValues = false;
+    private transient boolean staleAvailableValues;
 
-    private transient boolean errorOnReset = false;
+    private transient boolean errorOnReset;
     private transient boolean locked;
-    private int lastIndex = 0;
+    private int lastIndex;
+    
+    { clear(); }
+    
+    public UnicodeMap clear() {
+        if (locked) throw new UnsupportedOperationException("Attempt to modify locked object");
+        length = 2;
+        transitions = new int[] {0,0x110000,0,0,0,0,0,0,0,0};
+        values = new Object[10];
+        
+        availableValues.clear();
+        staleAvailableValues = false;
+
+        errorOnReset = false;
+        lastIndex = 0;
+    	return this;
+    }
     
     /* Boilerplate */
     public boolean equals(Object other) {
@@ -454,6 +471,10 @@ public final class UnicodeMap implements Cloneable, Freezable, Externalizable {
     public UnicodeSet getSet(Object value) {
         return getSet(value,null);
     }
+
+    public UnicodeSet keySet() {
+        return getSet(null,null).complement();
+    }
     /**
      * Returns the list of possible values. Deposits each non-null value into
      * result. Creates result if it is null. Remember to clear result if