code: static <K, V> boolean removeEntryImpl(Collection<Entry<K, V>> c, Object o) {
      if (!(o instanceof Entry)) {
        return false;
      }
      return c.remove(unmodifiableEntry((Entry<?, ?>) o));
    }
docs: Implements {@code Collection.remove} safely for forwarding collections of map entries. If
  {@code o} is an instance of {@code Entry}, it is wrapped using {@link #unmodifiableEntry} to
  protect against a possible nefarious equals method.
  
  <p>Note that {@code c} is backing (delegate) collection, rather than the forwarding collection.
  
  @param c the delegate (unwrapped) collection of map entries
  @param o the object to remove from {@code c}
  @return {@code true} if {@code c} was changed