Function minisign::sign

pub fn sign<W, R>(
    signature_box_writer: W, 
    pk: Option<&PublicKey>, 
    sk: &SecretKey, 
    data_reader: R, 
    prehashed: bool, 
    trusted_comment: Option<&str>, 
    untrusted_comment: Option<&str>
) -> Result<()> where
    W: Write,
    R: Read,