is_array method Null safety
Implementation
bool is_array() {
  final constructor = _dll_handle.lookupFunction<_Context_isArray_c, _Context_isArray_dart>(_context_namespace + 'isArray');
  final exception = _getException();
  bool res = constructor(this._impl, exception);
  tdvCheckException(exception, _dll_handle);
  return res;
}