def check( state_engine, nameop, block_id, checked_ops ):
    """
    Log an announcement from the blockstack developers,
    but first verify that it is correct.
    Return True if the announcement came from the announce IDs whitelist
    Return False otherwise
    """

    sender = nameop['sender']
    sending_blockchain_id = None
    found = False
    blockchain_namerec = None

    for blockchain_id in state_engine.get_announce_ids():
        blockchain_namerec = state_engine.get_name( blockchain_id )
        if blockchain_namerec is None:
            # this name doesn't exist yet, or is expired or revoked
            continue

        if str(sender) == str(blockchain_namerec['sender']):
            # yup!
            found = True
            sending_blockchain_id = blockchain_id
            break

    if not found:
        log.warning("Announcement not sent from our whitelist of blockchain IDs")
        return False

    nameop['announcer_id'] = sending_blockchain_id
    process_announcement( blockchain_namerec, nameop, state_engine.working_dir )
    return True
Log an announcement from the blockstack developers,
    but first verify that it is correct.
    Return True if the announcement came from the announce IDs whitelist
    Return False otherwise