code: def to_python(self, value):
          '''Handle data from serialization and form clean() methods.'''
          if isinstance(value, Seconds):
              return value
          if value in self.empty_values:
              return None
          return self.parse_seconds(valuef to_python(self, value):
          '''Handle data from serialization and form clean() methods.'''
          if isinstance(value, Seconds):
              return value
          if value in self.empty_values:
              return None
          return self.parse_seconds(value)
docs: Handle data from serialization and form clean() methods.