code: def handle_output(self, workunit, label, s):
      
      if not self.is_under_main_root(workunit):
        return
      tool_output_format = self._get_tool_output_format(workunit)
      if tool_output_format == ToolOutputFormat.INDENT:
        self.emit(self._prefix(workunit, s))
      elif tool_output_format == ToolOutputFormat.UNINDENTED:
        self.emit(s)
      self.flush()
docs: Implementation of Reporter callback.