Function proof_size 

pub fn proof_size<E: PairingEngine>(
    batch_sizes: &[usize],
    varuna_version: VarunaVersion,
    hiding: bool,
) -> Result<usize>

Computes the size in bytes of a Varuna proof as produced by Proof::serialize_compressed without needing to receive the proof itself.

Arguments:

• batch_sizes: the batch sizes of the circuits and instances being proved.
• varuna_version: the version of Varuna being used
• hiding: indicates whether the proof system is run in ZK mode

Returns:

• Ok(size) for VarunaVersion::V2, where size is the size of the proof in bytes.
• Err for VarunaVersion::V1.