code: def _select_class(self, line):
          
          g = self.current['graph']
          if not line:
              out = g.all_classes
              using_pattern = False
          else:
              using_pattern = True
              if line.isdigit():
                  line = int(line)
              out = g.get_class(line)
          if out:
              if type(out) == type([]):
                  choice = self._selectFromList(out, using_pattern, "class")
                  if choice:
                      self.currentEntity = {'name': choice.locale or choice.uri,
                                            'object': choice, 'type': 'class'}
              else:
                  self.currentEntity = {'name': out.locale or out.uri, 'object': out, 'type': 'class'}
              # ..finally:
              if self.currentEntity:
                  self._print_entity_intro(entity=self.currentEntity)
  
          else:
              print("not found")
docs: try to match a class and load it from the graph
          NOTE: the g.get_class(pattern) method does the heavy lifting