@Override 
	public T first() {
		if (elements instanceof SortedSet<?>)
			return ((SortedSet<T>) elements).first();
		if (elements instanceof List<?>)
			return ((List<T>) elements).get(0);
		return super.first();
	}
@ Override public T first ( ) { if ( elements instanceof SortedSet < ? > ) return ( ( SortedSet < T > ) elements ) . first ( ) ; if ( elements instanceof List < ? > ) return ( ( List < T > ) elements ) . get ( 0 ) ; return super . first ( ) ; }
{@inheritDoc}