### Question:
DefaultValueConfigurationSource extends AbstractConfigurationSource { public DefaultValueConfigurationSource(Map<String, String> keyValueMap) { super(Integer.MIN_VALUE, "DefaultValue"); _defaultValueConfiguration = new DefaultValueConfiguration(keyValueMap); } DefaultValueConfigurationSource(Map<String, String> keyValueMap); @Override DefaultValueConfiguration configuration();  }### Answer:
@Test public void defaultValueConfigurationSourceTest() { DefaultValueConfigurationSource defaultValueConfigurationSource = getDefaultValueConfigurationSource(); MemoryConfigurationSource memoryConfigurationSource = getMemoryConfigurationSource(); ConfigurationManager manager = ConfigurationManagers.newManager(defaultValueConfigurationSource, memoryConfigurationSource); String planet = manager.getPropertyValue(planetKey); String country = manager.getPropertyValue(countryKey); String city = manager.getPropertyValue(cityKey); Assert.assertEquals(planetDefaultValue, planet); Assert.assertEquals(countryValue, country); Assert.assertEquals(cityValue, city); }