Probe target
  repo: https://github.com/Emurgo/cardano-serialization-lib
  git HEAD: 6b4253814f1831fee06cda2718fd47174960ace1
  package version: 17.0.0 (rust/Cargo.toml)
  method: bundled docs plus shallow upstream API inspection

Inspected API
  rust/src/builders/tx_builder.rs
    TransactionBuilder::set_fee(&Coin)
    TransactionBuilder::add_change_if_needed(&Address)
    TransactionBuilder::build() -> TransactionBody
    TransactionBuilder::build_tx() -> Transaction
    TransactionBuilder::min_fee() -> Coin

add_change_if_needed mutates the fee and adds/adjusts change. Its documentation
requires calling it after all other body properties and warns that later edits
can invalidate the calculated fee. Outputs and redeemers are fixed builder
inputs; there is no callback receiving a candidate transaction. The mutable
builder plus build/min_fee/set_fee permits a caller-owned rebuild loop.