code: public boolean unsuspendCassandraHost(CassandraHost cassandraHost) {
      HClientPool pool = suspendedHostPools.remove(cassandraHost);
      boolean readded = pool != null;
      if ( readded ) {
        boolean alreadyThere = hostPools.putIfAbsent(cassandraHost, pool) != null;
        if ( alreadyThere ) {
          log.error("Unsuspend called on a pool that was already active for CassandraHost {}", cassandraHost);
          pool.shutdown();
        }
      }
      listenerHandler.fireOnUnSuspendHost(cassandraHost, readded);
      log.info("UN-Suspend operation status was {} for CassandraHost {}", readded, cassandraHost);
      return readded;
    }
docs: The opposite of suspendCassandraHost, places the pool back into selection
  @param cassandraHost
  @return true if this operation was successful. A no-op returning false
  if there was no such host in the underlying suspendedHostPool map.