@Test
public void testGenerateKey() {

  assertThat(CacheUtil.generateKey(Uri.EMPTY)).isNotNull();
  Uri testUri = Uri.parse("test");
  String key = CacheUtil.generateKey(testUri);
  assertThat(key).isNotNull();
  // Should generate the same key for the same input.
  assertThat(CacheUtil.generateKey(testUri)).isEqualTo(key);
  // Should generate different key for different input.
  assertThat(key.equals(CacheUtil.generateKey(Uri.parse("test2")))).isFalse();
}