def _convert_key(self, key, is_setter=False):
for a, i in zip(self.obj.axes, key):<EOL><INDENT>if not is_integer(i):<EOL><INDENT>raise ValueError("<STR_LIT>"<EOL>"<STR_LIT>")<EOL><DEDENT><DEDENT>return key<EOL>
require integer args (and convert to label arguments)