--- src/java/org/apache/commons/collections/MultiHashMap.java.orig	2019-10-04 16:36:43 UTC
+++ src/java/org/apache/commons/collections/MultiHashMap.java
@@ -331,21 +331,21 @@ public class MultiHashMap extends HashMap implements M
      * @param item  the value to remove
      * @return the value removed (which was passed in), null if nothing removed
      */
-    public Object remove(Object key, Object item) {
+    public boolean remove(Object key, Object item) {
         Collection valuesForKey = getCollection(key);
         if (valuesForKey == null) {
-            return null;
+            return false;
         }
         boolean removed = valuesForKey.remove(item);
         if (removed == false) {
-            return null;
+            return false;
         }
         // remove the list if it is now empty
         // (saves space, and allows equals to work)
         if (valuesForKey.isEmpty()){
             remove(key);
         }
-        return item;
+        return true;
     }
 
     /**
--- src/java/org/apache/commons/collections/MultiMap.java.orig	2019-10-04 16:36:43 UTC
+++ src/java/org/apache/commons/collections/MultiMap.java
@@ -66,7 +66,7 @@ public interface MultiMap extends Map {
      * @throws ClassCastException if the key or value is of an invalid type
      * @throws NullPointerException if the key or value is null and null is invalid
      */
-    public Object remove(Object key, Object item);
+    public boolean remove(Object key, Object item);
 
     //-----------------------------------------------------------------------
     /**
@@ -144,7 +144,7 @@ public interface MultiMap extends Map {
      * @throws ClassCastException if the key is of an invalid type
      * @throws NullPointerException if the key is null and null keys are invalid
      */
-    Object remove(Object key);
+    //boolean remove(Object key);
 
     /**
      * Gets a collection containing all the values in the map.
--- src/java/org/apache/commons/collections/map/MultiKeyMap.java.orig	2019-10-04 16:36:43 UTC
+++ src/java/org/apache/commons/collections/map/MultiKeyMap.java
@@ -197,7 +197,7 @@ public class MultiKeyMap
      * @param key2  the second key
      * @return the value mapped to the removed key, null if key not in map
      */
-    public Object remove(Object key1, Object key2) {
+    public boolean remove(Object key1, Object key2) {
         int hashCode = hash(key1, key2);
         int index = map.hashIndex(hashCode, map.data.length);
         AbstractHashedMap.HashEntry entry = map.data[index];
@@ -206,12 +206,14 @@ public class MultiKeyMap
             if (entry.hashCode == hashCode && isEqualKey(entry, key1, key2)) {
                 Object oldValue = entry.getValue();
                 map.removeMapping(entry, index, previous);
-                return oldValue;
+                //return oldValue;
+                return true;
             }
             previous = entry;
             entry = entry.next;
         }
-        return null;
+        //return null;
+        return false;
     }
 
     /**
--- src/java/org/apache/commons/collections/map/MultiValueMap.java.orig	2019-10-04 16:36:43 UTC
+++ src/java/org/apache/commons/collections/map/MultiValueMap.java
@@ -153,19 +153,19 @@ public class MultiValueMap extends AbstractMapDecorato
      * @param value the value to remove
      * @return the value removed (which was passed in), null if nothing removed
      */
-    public Object remove(Object key, Object value) {
+    public boolean remove(Object key, Object value) {
         Collection valuesForKey = getCollection(key);
         if (valuesForKey == null) {
-            return null;
+            return false;
         }
         boolean removed = valuesForKey.remove(value);
         if (removed == false) {
-            return null;
+            return false;
         }
         if (valuesForKey.isEmpty()) {
             remove(key);
         }
-        return value;
+        return true;
     }
 
     /**
--- src/test/org/apache/commons/collections/TestMultiHashMap.java.orig	2019-10-04 16:36:43 UTC
+++ src/test/org/apache/commons/collections/TestMultiHashMap.java
@@ -464,11 +464,11 @@ public class TestMultiHashMap extends AbstractTestMap 
         map.put("A", "AA");
         map.put("A", "AB");
         map.put("A", "AC");
-        assertEquals(null, map.remove("C", "CA"));
-        assertEquals(null, map.remove("A", "AD"));
-        assertEquals("AC", map.remove("A", "AC"));
-        assertEquals("AB", map.remove("A", "AB"));
-        assertEquals("AA", map.remove("A", "AA"));
+        assertEquals(false, map.remove("C", "CA"));
+        assertEquals(false, map.remove("A", "AD"));
+        assertEquals(true, map.remove("A", "AC"));
+        assertEquals(true, map.remove("A", "AB"));
+        assertEquals(true, map.remove("A", "AA"));
         assertEquals(new MultiHashMap(), map);
     }
 
--- src/test/org/apache/commons/collections/map/TestMultiKeyMap.java.orig	2019-10-04 16:36:43 UTC
+++ src/test/org/apache/commons/collections/map/TestMultiKeyMap.java
@@ -315,10 +315,10 @@ public class TestMultiKeyMap extends AbstractTestItera
             switch (key.size()) {
                 case 2:
                 assertEquals(true, multimap.containsKey(key.getKey(0), key.getKey(1)));
-                assertEquals(value, multimap.remove(key.getKey(0), key.getKey(1)));
+                assertEquals(true, multimap.remove(key.getKey(0), key.getKey(1)));
                 assertEquals(false, multimap.containsKey(key.getKey(0), key.getKey(1)));
                 assertEquals(size - 1, multimap.size());
-                assertEquals(null, multimap.remove(key.getKey(0), key.getKey(1)));
+                assertEquals(false, multimap.remove(key.getKey(0), key.getKey(1)));
                 assertEquals(false, multimap.containsKey(key.getKey(0), key.getKey(1)));
                 break;
                 case 3: