Function wascap::wasm::sign_buffer_with_claims

pub fn sign_buffer_with_claims(
    buf: impl AsRef<[u8]>, 
    mod_kp: KeyPair, 
    acct_kp: KeyPair, 
    expires_in_days: Option<u64>, 
    not_before_days: Option<u64>, 
    caps: Vec<String>, 
    tags: Vec<String>
) -> Result<Vec<u8>>