### Question:
AuthenticationKey implements ByteSequence { public ByteArray prefix() { return bytes.subseq(0, 16); } private  AuthenticationKey(ByteArray bytes); static AuthenticationKey fromPublicKey(PublicKey publicKey); static AuthenticationKey fromMultiSignaturePublicKey(MultiSignaturePublicKey publicKey); static AuthenticationKey fromPublicKey(java.security.PublicKey javaPublicKey); static AuthenticationKey fromByteArray(ByteArray bytes); static AuthenticationKey fromHexString(String hexString); ByteArray toByteArray(); ByteArray prefix(); @Override byte[] toArray(); @Override String toString();  }### Answer:
@Test public void testPrefix() { assertThat(AuthenticationKey.fromHexString(AUTH_KEY).prefix().toString(), is("14f98e36264b387e688ef7d4b18c718d")); }