@Test
public void findMissingUser() throws Exception {

    PublicKey publicKey = new PublicKey();
    publicKey.setFingerPrint(new byte[]{6,-49,-18,45,-68,69,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,});
    User nonUser = userStore.findUser(publicKey);
    assertNull(nonUser);
}