@Test public void testKeysSortedByValue() { OpenIntIntHashMap map = new OpenIntIntHashMap(); map.put((int) 11, (int) 22); map.put((int) 12, (int) 23); map.put((int) 13, (int) 24); map.put((int) 14, (int) 25); map.removeKey((int) 13); IntArrayList keys = new IntArrayList(); map.keysSortedByValue(keys); int[] keysArray = keys.toArray(new int[keys.size()]); assertArrayEquals(new int[] {11, 12, 14}, keysArray ); }