parameters: (name, action)
docstring: Register a new command available from the command line.
  
    name   -- The name of the command.
    action -- The function called by the command.
  
    Using --name node_list on the command line will call action with
    the node list as argument.
docstring_summary: Register a new command available from the command line.
docstring_tokens: Register a new command available from the command line .
function: def command_add(name, action):
    """Register a new command available from the command line.
  
    name   -- The name of the command.
    action -- The function called by the command.
  
    Using --name node_list on the command line will call action with
    the node list as argument.
    """
    _MODES[name] = action
function_tokens: def command_add ( name , action ) : _MODES [ name ] = action