class Hkdf {

    static byte[] hkdf(byte[] masterKey, byte[] salt, byte[] data) throws InvalidKeyException {
        checkNotNull(masterKey, "HKDF requires master key to be set.");
        checkNotNull(salt, "HKDF requires a salt.");
        checkNotNull(data, "No data provided to HKDF.");
        return hkdfSha256Expand(hkdfSha256Extract(masterKey, salt), data);
    }

    private  Hkdf();

}