code: private int compareToLFU( CacheEntry other ) {
  
          int cmp = compareReadCount( other );
          if ( cmp != 0 ) {
              return cmp;
          }
  
          cmp = compareTime( other );
          if ( cmp != 0 ) {
              return cmp;
          }
  
          return compareOrder( other );
      }
docs: Compares the read counts.
  @param other read count
  @return results