parse a uint32 value

def uint32(self, name):
        """parse a uint32 value"""
        self._assert_is_string(name)
        frame = self._next_frame()
        if len(frame) != 4:
            raise MessageParserError("Expected exacty 4 byte for uint32 value")
        (val,) = unpack("!I", frame)
        self.results.__dict__[name] = val
        return self