#NEWLINE# def computeExpression( self , constraint_collection ) : #NEWLINE# #INDENT# key = self . getKey ( ) #NEWLINE# hashable = key . isKnownToBeHashable ( ) #NEWLINE# if ( not hashable ) : #NEWLINE# #INDENT# constraint_collection . onExceptionRaiseExit ( TypeError ) #NEWLINE# #UNINDENT# if ( hashable is False ) : #NEWLINE# #INDENT# pass #NEWLINE# #UNINDENT# return ( self , None , None )