@Test
  public void testGetSystemOffsetDefault() {
    String system1OffsetDefault = "offset-system-1";
    String system2OffsetDefault = "offset-system-2";
    Config config = new MapConfig(ImmutableMap.of(
        // default.stream.samza.offset.default set
        String.format(SystemConfig.SYSTEM_DEFAULT_STREAMS_PREFIX_FORMAT, MOCK_SYSTEM_NAME1) + SAMZA_OFFSET_DEFAULT,
        system1OffsetDefault,
        // should not use this value since default.stream.samza.offset.default is set
        String.format(SystemConfig.SYSTEM_ID_PREFIX, MOCK_SYSTEM_NAME1) + SAMZA_OFFSET_DEFAULT, "wrong-value",
        // only samza.offset.default set
        String.format(SystemConfig.SYSTEM_ID_PREFIX, MOCK_SYSTEM_NAME2) + SAMZA_OFFSET_DEFAULT, system2OffsetDefault));
    SystemConfig systemConfig = new SystemConfig(config);
    assertEquals(system1OffsetDefault, systemConfig.getSystemOffsetDefault(MOCK_SYSTEM_NAME1));
    assertEquals(system2OffsetDefault, systemConfig.getSystemOffsetDefault(MOCK_SYSTEM_NAME2));
    assertEquals(SystemConfig.SAMZA_SYSTEM_OFFSET_UPCOMING, systemConfig.getSystemOffsetDefault("other-system"));
  }
Placeholder to help make sure the correct {@link SystemAdmin} is returned by {@link MockSystemFactory}. Do not mock
any methods of this mock.
samza-core/src/test/java/org/apache/samza/config/TestSystemConfig.java