code: def __redirect_stdio_emit(self, value):
          
          parent = self.parent()
          while parent is not None:
              try:
                  parent.redirect_stdio.emit(value)
              except AttributeError:
                  parent = parent.parent()
              else:
                  break
docs: Searches through the parent tree to see if it is possible to emit the
          redirect_stdio signal.
          This logic allows to test the SearchInComboBox select_directory method
          outside of the FindInFiles plugin.