Squash some SpotBugs warnings

Author: acogoluegnes

src/main/java/com/rabbitmq/client/amqp/impl/FastUtilIntComparator.java

@@ -18,6 +18,7 @@
 package com.rabbitmq.client.amqp.impl;
 
 
+import java.io.Serializable;
 import java.util.Comparator;
 
 /**
@@ -31,7 +32,7 @@
  * @see Comparator
  */
 @FunctionalInterface
-interface FastUtilIntComparator {
+interface FastUtilIntComparator extends Serializable {
   /**
    * Compares its two primitive-type arguments for order. Returns a negative integer, zero, or a
    * positive integer as the first argument is less than, equal to, or greater than the second.

src/main/java/com/rabbitmq/client/amqp/impl/FastUtilSwapper.java

@@ -16,12 +16,14 @@
 
 package com.rabbitmq.client.amqp.impl;
 
+import java.io.Serializable;
+
 /** An object that can swap elements whose position is specified by integers.
  *
  * @see Arrays#quickSort(int, int, it.unimi.dsi.fastutil.ints.IntComparator, Swapper)
  */
 @FunctionalInterface
-interface FastUtilSwapper {
+interface FastUtilSwapper extends Serializable {
 
   /** Swaps the data at the given positions.
    *

src/main/java/com/rabbitmq/client/amqp/impl/SerialNumberUtils.java

@@ -17,6 +17,7 @@
 // [email protected].
 package com.rabbitmq.client.amqp.impl;
 
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import java.util.*;
 import java.util.function.ToLongFunction;
 
@@ -90,7 +91,11 @@ static int compare(long s1, long s2) {
 
   private static class SerialNumberComparator<T> implements FastUtilIntComparator {
 
+    private static final long serialVersionUID = -1979133464402603205L;
+
     private final List<T> list;
+
+    @SuppressFBWarnings("SE_BAD_FIELD")
     private final ToLongFunction<T> serialNumberExtractor;
 
     private SerialNumberComparator(List<T> list, ToLongFunction<T> serialNumberExtractor) {
@@ -108,6 +113,7 @@ public int compare(int k1, int k2) {
 
   private static final class ListSwapper<T> implements FastUtilSwapper {
 
+    private static final long serialVersionUID = -4992779583870196665L;
     private final List<T> list;
 
     private ListSwapper(List<T> list) {