code: def handle_get_vts_command(self, vt_et):
          
  
          vt_id = vt_et.attrib.get('vt_id')
          vt_filter = vt_et.attrib.get('filter')
  
          if vt_id and vt_id not in self.vts:
              text = "Failed to find vulnerability test '{0}'".format(vt_id)
              return simple_response_str('get_vts', 404, text)
  
          filtered_vts = None
          if vt_filter:
              filtered_vts = self.vts_filter.get_filtered_vts_list(
                  self.vts, vt_filter)
  
          responses = []
  
          vts_xml = self.get_vts_xml(vt_id, filtered_vts)
  
          responses.append(vts_xml)
  
          return simple_response_str('get_vts', 200, 'OK', responses)
docs: Handles <get_vts> command.
  
          @return: Response string for <get_vts> command.