def get_pb_id_from_deploy_id(deploy_id: str) -> str:
    """Get processing block ID from deployment ID.

    This assumes that all deployments associated with a processing
    block of ID `[type]-[date]-[number]` have a deployment ID of the
    form `[type]-[date]-[number]-*`.
    """
    return '-'.join(deploy_id.split('-')[0:3])