code: def append_if_provenance_step(
              self, title, description, timestamp=None, data=None):
          
          step_time = self._provenance.append_if_provenance_step(
              title, description, timestamp, data)
          if step_time > self.last_update:
              self.last_update = step_time
docs: Add a if provenance step to the provenance of the metadata
  
          :param title: The title of the step.
          :type title: str
  
          :param description: The content of the step
          :type description: str
  
          :param timestamp: the time of the step
          :type timestamp: datetime, str
  
          :param data: The data of the step.
          :type data: dict