public override bool Equals(Object o)
            {
                if (!(o is ClusterClusterPair))
                {
                    return(false);
                }
                ClusterClusterPair other = (ClusterClusterPair)o;

                return(cluster1.Equals(other.getCluster1()) &&
                       cluster2.Equals(other.getCluster2()) &&
                       similarity == other.getSimilarity());
            }