code: def print_help(self):
          
          seen_aliases = set()
          print('-'*80)
          for cmd in sorted(self.cmds):
              if cmd not in self.builtin_cmds:
                  if cmd not in seen_aliases:
                      if cmd in self.aliases:
                          seen_aliases.update(self.aliases[cmd])
                          disp = '/'.join(self.aliases[cmd])
                      else:
                          disp = cmd
                      _, parser = self.cmds[cmd]
                      usage = parser.format_usage()
                      print('%s: %s' % (disp, ' '.join(usage.split()[2:])))
          print('External CLIs: %s' % ', '.join(sorted(self.clis)))
docs: Prints usage of all registered commands, collapsing aliases
          into one record