### Question:
AvatarUpdatedKeyBuilder { public String buildKey(final AvatarType avatarType) { return String.format(KEY_FORMAT, avatarType.getId()); }  String buildKey(final AvatarType avatarType);  }### Answer:
@Test public void buildKeyTest() { assertEquals( "avatar_updated:gravatar", keyBuilder.buildKey(AvatarType.GRAVATAR)); }