Macro domain_separator 

macro_rules! domain_separator {
    ($fmt:literal $(, $arg:expr)* $(,)? ; $sess_fmt:literal $(, $sess_arg:expr)* $(,)?) => { ... };
    ($fmt:literal $(, $arg:expr)* $(,)? ; $session:expr $(,)?) => { ... };
    ($fmt:literal $(, $arg:expr)* $(,)?) => { ... };
}

Build a DomainSeparator from a formatted string.

let domsep = spongefish::domain_separator!("spongefish"; "DomainSeparator")
    .instance(b"trivial");
let _prover = domsep.std_prover();