Create bytes from properties

def to_bytes(self):
        '''
        Create bytes from properties
        '''
        # Check properties
        self.sanitize()

        # Start with reserved bits
        bitstream = self._to_rsvd1()

        # Add zeroes for the flags
        bitstream += self._to_flags()

        # Add the type
        bitstream += BitArray('uint:8=%d' % self.lcaf_type)

        # Some more reserved bits
        bitstream += self._to_rsvd2()

        # Construct the data
        data = self._to_data_bytes()

        # Add the length
        data_length = data.len / 8
        bitstream += BitArray('uint:16=%d' % data_length)

        return (bitstream + data).bytes