private void assertUserAssignment(
      JdoUserAssignment expectedAssignment, JdoUserAssignment assignment) {
    SimpleDateFormat sdf = new SimpleDateFormat("EEE, d MMM yyyy HH:mm:ss Z", Locale.US);
    assertNotNull(expectedAssignment.getTimestamp());
    assertNotNull(assignment.getTimestamp());

    assertEquals(
        sdf.format(expectedAssignment.getTimestamp()), sdf.format(assignment.getTimestamp()));
    assertEquals(expectedAssignment.getRoleNames(), assignment.getRoleNames());
  }