public static boolean keyExists(final String key, final String... providedKeys) {
        Objects.requireNonNull(key);
        if (Graph.Hidden.isHidden(key)) return false;
        if (null == providedKeys || 0 == providedKeys.length) return true;
        if (1 == providedKeys.length) return key.equals(providedKeys[0]);
        else {
            for (final String temp : providedKeys) {
                if (key.equals(temp))
                    return true;
            }
            return false;
        }
    }
Checks if a key exists within a list of provided keys. Returns {@code false} if the key is {@code null} or if
the {@link Graph.Hidden}. Returns {@code true} if no {@code providedKeys} are supplied.

@param key must not be {@code null}
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/structure/util/ElementHelper.java