An atomic transaction that contains a set of digital signatures of a serialized [`Message`], signed by the first `signatures.len()` keys of [`account_keys`].

Token balance changes as a result of a transaction Docs: https://docs.solana.com/developing/clients/jsonrpc-api#token-balances-structure Source: https://github.com/solana-labs/solana/blob/master/transaction-status/src/token_balances.rs.