code: def _get_xml(self, close_tag=True):
          
  
          provenance_step_element = Element('provenance_step', {
              'timestamp': self.time.isoformat()
          })
          title = SubElement(provenance_step_element, 'title')
          title.text = self.title
          description = SubElement(provenance_step_element, 'description')
          description.text = self.description
  
          xml_string = tostring(provenance_step_element, 'unicode')
  
          if close_tag:
              return xml_string
          else:
              # Remove the close tag
              return xml_string[:-len('</provenance_step>')]
docs: generate the xml string representation.
  
          :param close_tag: should the '</provenance_step>' tag be added or not.
          :type close_tag: bool
  
          :return: the xml
          :rtype: str