code: def do_back(self, line):
          "Go back one step. From entity => ontology; from ontology => ontospy top level."
          if self.currentEntity:
              self.currentEntity = None
              self.prompt = _get_prompt(self.current['file'])
          else:
              self.current = None
              self.prompt = _get_prompt(f do_back(self, line):
          "Go back one step. From entity => ontology; from ontology => ontospy top level."
          if self.currentEntity:
              self.currentEntity = None
              self.prompt = _get_prompt(self.current['file'])
          else:
              self.current = None
              self.prompt = _get_prompt()
docs: Go back one step. From entity => ontology; from ontology => ontospy top level.