def __setitem__(self, extension_handle, value):
_VerifyExtensionHandle(self._extended_message, extension_handle)<EOL>if (extension_handle.label == _FieldDescriptor.LABEL_REPEATED or<EOL>extension_handle.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE):<EOL><INDENT>raise TypeError(<EOL>'<STR_LIT>'<EOL>'<STR_LIT>' % extension_handle.full_name)<EOL><DEDENT>type_checker = type_checkers.GetTypeChecker(extension_handle)<EOL>self._extended_message._fields[extension_handle] = (<EOL>type_checker.CheckValue(value))<EOL>self._extended_message._Modified()<EOL>
If extension_handle specifies a non-repeated, scalar extension
        field, sets the value of that field.