### Question:
UscAddress { public static UscAddress nullAddress() { return NULL_ADDRESS; } UscAddress(DataWord address);  UscAddress(String address);  UscAddress(byte[] bytes); private  UscAddress(); static UscAddress nullAddress(); byte[] getBytes(); @Override boolean equals(Object other); @Override int hashCode(); @Override String toString(); static final Comparator<UscAddress> LEXICOGRAPHICAL_COMPARATOR; }### Answer:
@Test public void nullAddress() { UscAddress senderA = new UscAddress("0000000000000000000000000000000000000000"); UscAddress senderB = new UscAddress("0x0000000000000000000000000000000000000000"); UscAddress senderC = new UscAddress(new byte[20]); UscAddress senderD = new UscAddress("0000000000000000000000000000000000000001"); Assert.assertEquals(UscAddress.nullAddress(), senderA); Assert.assertEquals(UscAddress.nullAddress(), senderB); Assert.assertEquals(UscAddress.nullAddress(), senderC); Assert.assertNotEquals(UscAddress.nullAddress(), senderD); }