#NEWLINE# def __init__( self , key_type , value_type , default = dict , **kwargs ) : #NEWLINE# #INDENT# '\n        :param key_type: a column class indicating the types of the key\n        :param value_type: a column class indicating the types of the value\n        ' #NEWLINE# super ( Map , self ) . __init__ ( ( key_type , value_type ) , default = default , ** kwargs ) #NEWLINE# self . key_col = self . types [ 0 ] #NEWLINE# self . value_col = self . types [ 1 ] #NEWLINE# if ( not self . key_col . _python_type_hashable ) : #NEWLINE# #INDENT# raise ValidationError ( 'Cannot create a Map with unhashable key type (see PYTHON-494)' ) #NEWLINE# #UNINDENT# self . db_type = 'map<{0}, {1}>' . format ( self . key_col . db_type , key_type . value_col . db_type )