* are off).
       */
      KeyList<K, V> keyList = requireNonNull(keyToKeyList.remove(node.key));
      keyList.count = 0;
      modCount++;
    } else {
      // requireNonNull is safe (under the conditions listed in the comment in the branch above).
      KeyList<K, V> keyList = requireNonNull(keyToKeyList.get(node.key));
      keyList.count--;

      if (node.previousSibling == null) {

       * are off).
       */
      KeyList<K, V> keyList = requireNonNull(keyToKeyList.remove(node.key));
      keyList.count = 0;
      modCount++;
    } else {
      // requireNonNull is safe (under the conditions listed in the comment in the branch above).
      KeyList<K, V> keyList = requireNonNull(keyToKeyList.get(node.key));
      keyList.count--;

      if (node.previousSibling == null) {

        not(not -> not.setKey_Term(key), opLambda);
    }

    public void setKey_Terms(Collection<String> keyList) {
        setKey_Terms(keyList, null);
    }

    public void setKey_Terms(Collection<String> keyList, ConditionOptionCall<TermsQueryBuilder> opLambda) {
        TermsQueryBuilder builder = regTermsQ("key", keyList);
        if (opLambda != null) {
            opLambda.callback(builder);
        }
    }

    }
  }

  @Override
  ImmutableSet<K> createKeySet() {
    @SuppressWarnings("unchecked")
    ImmutableList<K> keyList =
        (ImmutableList<K>) new KeysOrValuesAsList(alternatingKeysAndValues, 0, size);
    return new KeySet<K>(this, keyList);
  }

  static final class KeysOrValuesAsList extends ImmutableList<Object> {
    private final transient @Nullable Object[] alternatingKeysAndValues;