<s> class ModelCollection ( list ) : <EOL> """<STR_LIT>""" <EOL> def __init__ ( self , field ) : <EOL> self . field = field <EOL> def append ( self , value ) : <EOL> self . field . validate_single_value ( value ) <EOL> super ( ModelCollection , self ) . append ( value ) <EOL> def __setitem__ ( self , key , value ) : <EOL> self . field . validate_single_value ( value ) <EOL> super ( ModelCollection , self ) . __setitem__ ( key , value ) </s>
