code: def handle_source_positions(self, call_id, payload):
          
          self.log.debug('handle_source_positions: in %s', Pretty(payload))
  
          call_options = self.call_options[call_id]
          word_under_cursor = call_options.get("word_under_cursor")
  
          positions = payload["positions"]
  
          if not positions:
              self.editor.raw_message("No usages of <{}> found".format(word_under_cursor))
              return
  
          qf_list = []
          for p in positions:
              position = p["position"]
              preview = str(p["preview"]) if "preview" in p else "<no preview>"
              item = self.editor.to_quickfix_item(str(position["file"]),
                                                  position["line"],
                                                  preview,
                                                  "info")
              qf_list.append(item)
          qf_sorted = sorted(qf_list, key=itemgetter('filename', 'lnum'))
          self.editor.write_quickfix_list(qf_sorted, "Usages of <{}>".format(word_under_cursor))
docs: Handler for source positions