/**
  * This can receive either a <code>CompositeCollection.CollectionMutator</code>
  * or a <code>CompositeSet.SetMutator</code>. If a
  * <code>CompositeCollection.CollectionMutator</code> is used than conflicts when adding
  * composited sets will throw IllegalArgumentException
  * <p>
  */
 public override void setMutator(CollectionMutator mutator)
 {
     base.setMutator(mutator);
 }
        //-----------------------------------------------------------------------

        /**
         * Specify a CollectionMutator strategy instance to handle changes.
         *
         * @param mutator  the mutator to use
         */
        public virtual void setMutator(CollectionMutator mutator)
        {
            this.mutator = mutator;
        }