@staticmethod
def create_meta(asset_id, source='Cisco', padding='0'):
    """
        The metadata format is:
        key_id + ',' + Cisco + '00000...'

        till 256  bytes

        :param asset_id: Asset UUID
        :param source: Cisco
        :param padding: 0
        :return: metadata bytearray.
        """
    metadata = bytearray()
    metadata.extend(map(ord, asset_id + ','))
    metadata.extend(map(ord, source))
    while len(metadata) != 256:
        metadata.extend(map(ord, padding))
    return metadata
