### Question:
QualifiedPathKey implements Comparable<Object> { public String getNamespace() { return namespace; } QualifiedPathKey(String cluster, String path);  QualifiedPathKey(String cluster, String path, String namespace); String getCluster(); String getPath(); String getNamespace(); @Override String toString(); @Override int compareTo(Object other); @Override int hashCode(); @Override boolean equals(Object other); boolean hasFederatedNS();  }### Answer:
@Test public void testConstructor1() throws Exception { QualifiedPathKey key1 = new QualifiedPathKey(cluster1, path1); testKeyComponents(key1); assertNull(key1.getNamespace()); }
@Test public void testConstructor2() throws Exception { QualifiedPathKey key1 = new QualifiedPathKey(cluster1, path1, namespace1); testKeyComponents(key1); assertNotNull(key1.getNamespace()); assertEquals(key1.getNamespace(), namespace1); }