Function build_vid_proposal 

pub async fn build_vid_proposal<TYPES: NodeType, V: Versions>(
    membership: &EpochMembership<TYPES>,
    view_number: TYPES::View,
    epoch_number: Option<TYPES::Epoch>,
    payload: &TYPES::BlockPayload,
    metadata: &<TYPES::BlockPayload as BlockPayload<TYPES>>::Metadata,
    private_key: &<TYPES::SignatureKey as SignatureKey>::PrivateKey,
    upgrade_lock: &UpgradeLock<TYPES, V>,
) -> (Proposal<TYPES, VidDisperse<TYPES>>, Vec<Proposal<TYPES, VidDisperseShare<TYPES>>>)