if (returnFiber.type !== 'textarea') {
    let addendum = '';
    if (__DEV__) {
      addendum =
        ' If you meant to render a collection of children, use an array ' +
        'instead.' +
        (getCurrentFiberStackAddendum() || '');
    }
    invariant(
      false,
      'Objects are not valid as a React child (found: %s).%s',
      Object.prototype.toString.call(newChild) === '[object Object]'
        ? 'object with keys {' + Object.keys(newChild).join(', ') + '}'
        : newChild,
      addendum,
    );
  }
}
function warnOnFunctionType() {