code: def toxml(self):
          
  
          chxmlstr = ''
  
          for run in self.runs:
              chxmlstr += run.toxml()
  
          for record in self.records:
              chxmlstr += record.toxml()
  
          for event_record in self.event_records:
              chxmlstr += event_record.toxml()
  
          for data_display in self.data_displays:
              chxmlstr += data_display.toxml()
  
          for data_writer in self.data_writers:
              chxmlstr += data_writer.toxml()
  
          for event_writer in self.event_writers:
              chxmlstr += event_writer.toxml()
  
          if chxmlstr:
              xmlstr = '<Simulation>' + chxmlstr + '</Simulation>'
          else:
              xmlstr = ''
  
          return xmlstr
docs: Exports this object into a LEMS XML object