code: public boolean isConsistent(Collection<? extends V> master) {
  
          Collection<? extends V> collection = this.collection;
  
          return collection.containsAll(master) && master.containsAll(collection);
      }
docs: Return whether this {@link RoundRobin} is still consistent and contains all items from the master {@link Collection} and
  vice versa.
  
  @param master the master collection containing source elements for this {@link RoundRobin}.
  @return {@literal true} if this {@link RoundRobin} is consistent with the master {@link Collection}.