### Question:
CArray extends CValue { @Override public Set<String> referencedKeys() { Set<String> referencedKeys = new HashSet<String>(); for (CValue value : data) { referencedKeys.addAll(value.referencedKeys()); } return referencedKeys; } CArray(final List<CValue> data); List<CValue> data(); @Override Set<String> referencedKeys(); @Override void replace(String key, String resolvedValue); @Override boolean equals(final Object o); @Override int hashCode(); @Override String toString();  }### Answer:
@Test public void testReferencedKeys() throws Exception { assertEquals(0, cArray.referencedKeys().size()); }