def read_var_uint32(self):
        """Reads a varint from the stream, interprets this varint
        as an unsigned, 32-bit integer, and returns the integer.
        """
        i = self.read_var_uint64()
        if i > wire_format.UINT32_MAX:
            raise errors.DecodeError('Value out of range for uint32: %d' % i)
        return i