def CheckValue(self, proposed_value):
if not isinstance(proposed_value, self._acceptable_types):<EOL><INDENT>message = ('<STR_LIT>' %<EOL>(proposed_value, type(proposed_value), self._acceptable_types))<EOL>raise TypeError(message)<EOL><DEDENT>return proposed_value<EOL>
Type check the provided value and return it.

        The returned value might have been normalized to another type.