#NEWLINE# def GetGtfsClassByFileName( self , filename ) : #NEWLINE# #INDENT# 'Returns the transitfeed class corresponding to a GTFS file.\n\n    Args:\n      filename: The filename whose class is to be returned\n\n    Raises:\n      NonStandardMapping if the specified filename has more than one\n          corresponding class\n    ' #NEWLINE# if ( filename not in self . _file_mapping ) : #NEWLINE# #INDENT# return None #NEWLINE# #UNINDENT# mapping = self . _file_mapping [ filename ] #NEWLINE# class_list = mapping [ 'classes' ] #NEWLINE# if ( len ( class_list ) > 1 ) : #NEWLINE# #INDENT# raise problems . NonStandardMapping ( self ) #NEWLINE# #UNINDENT# else : #NEWLINE# #INDENT# return self . _class_mapping [ class_list [ 0 ] ]