parameters: (self, args, screen_info=None)
return_statement: return screen_output
docstring: Step once.
  
      Args:
        args: (list of str) command-line arguments for the "step" command.
        screen_info: Information about screen.
  
      Returns:
        (RichTextLines) Screen output for the result of the stepping action.
docstring_summary: Step once.
docstring_tokens: Step once .
function: def step(self, args, screen_info=None):
      """Step once.
  
      Args:
        args: (list of str) command-line arguments for the "step" command.
        screen_info: Information about screen.
  
      Returns:
        (RichTextLines) Screen output for the result of the stepping action.
      """
  
      parsed = self.arg_parsers["step"].parse_args(args)
  
      if parsed.num_times < 0:
        return debugger_cli_common.RichTextLines(
            "ERROR: Invalid number of times to step: %d" % parsed.num_times)
  
      for _ in xrange(parsed.num_times):
        if self._next >= len(self._sorted_nodes):
          return debugger_cli_common.RichTextLines(
              "ERROR: Cannot step any further because the end of the sorted "
              "transitive closure has been reached.")
        else:
          screen_output = self.cont([self._sorted_nodes[self._next]], screen_info)
  
      return screen_output
function_tokens: def step ( self , args , screen_info = None ) : parsed = self . arg_parsers [ "step" ] . parse_args ( args ) if parsed . num_times < 0 : return debugger_cli_common . RichTextLines ( "ERROR: Invalid number of times to step: %d" % parsed . num_times ) for _ in xrange ( parsed . num_times ) : if self . _next >= len ( self . _sorted_nodes ) : return debugger_cli_common . RichTextLines ( "ERROR: Cannot step any further because the end of the sorted " "transitive closure has been reached." ) else : screen_output = self . cont ( [ self . _sorted_nodes [ self . _next ] ] , screen_info ) return screen_output