docs: def check_command(self, **new_attributes):
          """
          Check if 'was passed a valid action in the command line and if so,
          executes it by passing parameters and returning the result.
  
          :return: (Any) Return the result of the called function, if provided,
                   or None.
          """
          # let's parse arguments if we didn't before.
          if not self._is_parsed:
              self.parse_args()
          if not self.commands:
              # if we don't have commands raise an Exception
              raise exceptions.ArgParseInatorNoCommandsFound
          elif self._single:
              # if we have a single function we get it directly
              func = self._single
          else:
              if not self.args.command:
                  self.parser.error("too few arguments")
              # get the right command
              func = self.commands[self.args.command]
  
          if hasattr(func, '__subcommands__') and func.__subcommands__:
              # if we have subcommands get the command from them
              command = func.__subcommands__[self.args.subcommand]
          else:
              # else the command IS the function
              command = func
          # get the command name
          self.cmd_name = command.__cmd_name__
          # check authorization
          if not self.check_auth(id(command)):
              return 0
          # let's execute the command.
          return self._execute(func, command, **new_attributes)