True if the block which mined the deposit transaction has been
    confirmed.

def is_deposit_confirmed(
        channel_state: NettingChannelState,
        block_number: BlockNumber,
) -> bool:
    """True if the block which mined the deposit transaction has been
    confirmed.
    """
    if not channel_state.deposit_transaction_queue:
        return False

    return is_transaction_confirmed(
        channel_state.deposit_transaction_queue[0].block_number,
        block_number,
    )