private void singleValueInMapAsserts(Map<Long, String> map, Long testKey, String value) {
        assertEquals(value, map.get(testKey));
        assertEquals(1, map.size());
        assertFalse(map.isEmpty());
        assertTrue(map.containsKey(testKey));
        assertTrue(map.containsValue(value));
    }
This test demonstrates a retention issue in the NBHM implementation which keeps old keys around until a resize
event.
See https://github.com/JCTools/JCTools/issues/354
jctools-core/src/test/java/org/jctools/maps/NBHMRemoveTest.java