### Question:
ConfigValueMapStringView extends AbstractMap<String, ConfigValue> { @Override public boolean containsValue(final Object value) { ConfigValue configValue = (ConfigValue) value; if (configValue == null || configValue.getValue() == null) { return delegate.containsValue(null); } return delegate.containsValue(configValue.getValue()); } ConfigValueMapStringView(final Map<String, String> delegate, final String configSourceName,
            final int configSourceOrdinal); @Override int size(); @Override boolean isEmpty(); @Override boolean containsKey(final Object key); @Override boolean containsValue(final Object value); @Override ConfigValue get(final Object key); @Override Set<String> keySet(); @Override Set<Map.Entry<String, ConfigValue>> entrySet(); @Override Collection<ConfigValue> values();  }### Answer:
@Test public void containsValue() { final Map<String, ConfigValue> map = sampleMap(); assertTrue(map.containsValue(ConfigValue.builder().withValue("1234").build())); assertTrue(map.containsValue(null)); }