code: def get_value(self, index=None):
          
  
          if self.value is None:
              return self.default
          if index is not None:
              if self.value[index] is None:
                  return self.default
              else:
                  value = self.value[index]
          else:
              value = self.value
  
          return value
docs: Returns the default if value is none.
          :param index:
          :return: A value.