### Question:
CSN implements Serializable, Comparable<CSN> { public static int compare(CSN csn1, CSN csn2) { if (csn1 == null) { return csn2 == null ? 0 : -1; } else if (csn2 == null) { return 1; } else if (csn1.timeStamp != csn2.timeStamp) { return csn1.timeStamp < csn2.timeStamp ? -1 : 1; } else if (csn1.seqnum != csn2.seqnum) { return csn1.seqnum - csn2.seqnum; } else { return csn1.serverId - csn2.serverId; } } CSN(String str);  CSN(long timeStamp, int seqNum, int serverId); static CSN valueOf(String s); static CSN valueOf(ByteSequence bs); long getTime(); long getTimeSec(); int getSeqnum(); int getServerId(); @Override boolean equals(Object obj); @Override int hashCode(); ByteString toByteString(); void toByteString(ByteStringBuilder builder); @Override String toString(); String toStringUI(); static int compare(CSN csn1, CSN csn2); static int diffSeqNum(CSN csn1, CSN csn2); boolean isOlderThan(CSN csn); boolean isOlderThanOrEqualTo(CSN csn); boolean isNewerThanOrEqualTo(CSN csn); boolean isNewerThan(CSN csn); @Override int compareTo(CSN csn); static final int BYTE_ENCODING_LENGTH; static final int STRING_ENCODING_LENGTH; static final CSN MAX_CSN_VALUE; }### Answer:
@Test(dataProvider = "createCSN") public void csnCompare(CSN csn1, CSN csn2, CSN csn3, CSN csn4, CSN csn5) throws Exception { assertTrue(CSN.compare(null, null) == 0); assertTrue(CSN.compare(null, csn2) < 0); assertTrue(CSN.compare(csn1, null) > 0); assertTrue(CSN.compare(csn1, csn2) == 0); assertTrue(CSN.compare(csn1, csn3) < 0); assertTrue(CSN.compare(csn3, csn1) > 0); assertTrue(CSN.compare(csn1, csn4) < 0); assertTrue(CSN.compare(csn4, csn1) > 0); assertTrue(CSN.compare(csn1, csn5) < 0); assertTrue(CSN.compare(csn5, csn1) > 0); }