createFinder method Null safety

Implementation

Finder createFinder(SerializableFinder finder) {
  final String finderType = finder.finderType;
  switch (finderType) {
    case 'ByText':
      return _createByTextFinder(finder as ByText);
    case 'ByTooltipMessage':
      return _createByTooltipMessageFinder(finder as ByTooltipMessage);
    case 'BySemanticsLabel':
      return _createBySemanticsLabelFinder(finder as BySemanticsLabel);
    case 'ByValueKey':
      return _createByValueKeyFinder(finder as ByValueKey);
    case 'ByType':
      return _createByTypeFinder(finder as ByType);
    case 'PageBack':
      return _createPageBackFinder();
    case 'Ancestor':
      return _createAncestorFinder(finder as Ancestor);
    case 'Descendant':
      return _createDescendantFinder(finder as Descendant);
    default:
      throw DriverError('Unsupported search specification type $finderType');
  }
}