code: def get_feature_flag_by_name(self, name, check_feature_exists=None):
          
          route_values = {}
          if name is not None:
              route_values['name'] = self._serialize.url('name', name, 'str')
          query_parameters = {}
          if check_feature_exists is not None:
              query_parameters['checkFeatureExists'] = self._serialize.query('check_feature_exists', check_feature_exists, 'bool')
          response = self._send(http_method='GET',
                                location_id='3e2b80f8-9e6f-441e-8393-005610692d9c',
                                version='5.0-preview.1',
                                route_values=route_values,
                                query_parameters=query_parameters)
          return self._deserialize('FeatureFlag', response)
docs: GetFeatureFlagByName.
          [Preview API] Retrieve information on a single feature flag and its current states
          :param str name: The name of the feature to retrieve
          :param bool check_feature_exists: Check if feature exists
          :rtype: :class:`<FeatureFlag> <azure.devops.v5_0.feature_availability.models.FeatureFlag>`