#NEWLINE# @ _generative #NEWLINE# def where( self , whereclause ) : #NEWLINE# #INDENT# 'return a new update() construct with the given expression added to\n        its WHERE clause, joined to the existing clause via AND, if any.\n\n        ' #NEWLINE# if ( self . _whereclause is not None ) : #NEWLINE# #INDENT# self . _whereclause = and_ ( self . _whereclause , _literal_as_text ( self ) ) #NEWLINE# #UNINDENT# else : #NEWLINE# #INDENT# self . _whereclause = _literal_as_text ( whereclause )