@Override public boolean remove( final Object o ) {
        if( !(o instanceof Map.Entry)) return false;
        final Map.Entry<?,?> e = (Map.Entry<?,?>)o;
        return NonBlockingHashMap.this.remove(e.getKey(), e.getValue());
      }
Returns a {@link Set} view of the mappings contained in this map.  The
 set is backed by the map, so changes to the map are reflected in the
 set, and vice-versa.  The set supports element removal, which removes
 the corresponding mapping from the map, via the
 <tt>Iterator.remove</tt>, <tt>Set.remove</tt>, <tt>removeAll</tt>,
 <tt>retainAll</tt>, and <tt>clear</tt> operations.  It does not support
 the <tt>add</tt> or <tt>addAll</tt> operations.

 <p>The view's <tt>iterator</tt> is a "weakly consistent" iterator
 that will never throw {@link ConcurrentModificationException},
 and guarantees to traverse elements as they existed upon
 construction of the iterator, and may (but is not guaranteed to)
 reflect any modifications subsequent to construction.

 <p><strong>Warning:</strong> the iterator associated with this Set
 requires the creation of {@link java.util.Map.Entry} objects with each
 iteration.  The {@link NonBlockingHashMap} does not normally create or
 using {@link java.util.Map.Entry} objects so they will be created soley
 to support this iteration.  Iterating using {@link Map#keySet} or {@link
 Map#values} will be more efficient.
jctools-core/src/main/java/org/jctools/maps/NonBlockingHashMap.java