@Test
public void testReadId() {

  RandomIdProvider provider = new RandomIdProvider();
  assertNull(provider.readId("ABCDEFG"));
  assertNull(provider.readId(""));
  assertNull(provider.readId(null));
  assertEquals("ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE",
      provider.readId("ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE"));
}