question: public void add ( Comparable x ) { items . add ( null ) ; size += 1 ; int hole = size ; items . set ( 0 , x ) ; for ( ; x . compareTo ( items . get ( hole / 2 ) ) < 0 ; hole /= 2 ) { items . set ( hole , items . get ( hole / 2 ) ) ; } items . set ( hole , x ) ; }
target:  Insert into the priority queue. Duplicates are allowed.