def  METHOD_NAME( self, index_filename = None ):
    output = None
    if index_filename:
        output = open_output( index_filename )
    self.index_enter()
    for name in self.block_index:
        self.index_name_enter( name )
        self.index_name_exit( name )
    self.index_exit()
    if output:
        close_output( output )