#NEWLINE# def construct( cls , * args , **kwargs ) : #NEWLINE# #INDENT# cls = super ( RelayMutationMeta , cls ) . construct ( * cls , ** kwargs ) #NEWLINE# if ( not cls . _meta . abstract ) : #NEWLINE# #INDENT# assert hasattr ( cls , 'mutate_and_get_payload' ) , 'You have to implement mutate_and_get_payload' #NEWLINE# #UNINDENT# return cls