Function token_shielded_transfer_extra_sighash_data 

pub fn token_shielded_transfer_extra_sighash_data(
    token_id: &[u8; 32],
    owner_id: &[u8; 32],
    platform_version: &PlatformVersion,
) -> Result<Vec<u8>, ProtocolError>

Builds the transparent extra_data bound into a TokenShieldedTransfer’s platform sighash, with the byte layout token_id (32) || owner_id (32).

Nothing leaves the pool, so there is no amount or destination to bind, but the bundle is still pinned to one token pool and to the identity that pays for it: the same bundle cannot be resubmitted under another fee payer, and the pool it spends from is explicit.