def key_type(self, type_):
if not self.is_mapping(type_):<EOL><INDENT>raise TypeError(<EOL>'<STR_LIT>' %<EOL>str(type_))<EOL><DEDENT>return self.__find_xxx_type(<EOL>type_,<EOL>self.key_type_index,<EOL>self.key_type_typedef,<EOL>'<STR_LIT>')<EOL>
returns reference to the class key type declaration