fn labeled_extract_for_expand(
hkdf: &'static dyn HkdfPrkExtract,
suite_id: LabeledSuiteId,
salt: Option<&[u8]>,
label: Label,
ikm: &[u8],
) -> Box<dyn HkdfExpander>
fn labeled_extract_for_expand(
hkdf: &'static dyn HkdfPrkExtract,
suite_id: LabeledSuiteId,
salt: Option<&[u8]>,
label: Label,
ikm: &[u8],
) -> Box<dyn HkdfExpander>