#NEWLINE# def set_before( self , command_name , command_name_prev ) : #NEWLINE# #INDENT# 'Set command_name_prev to be run before command_name' #NEWLINE# self . _register ( command_name ) #NEWLINE# self . _register ( command_name_prev ) #NEWLINE# if ( not ( command_name_prev in self . before [ command_name ] ) ) : #NEWLINE# #INDENT# self . before [ command_name ] . append ( command_name_prev )