question: public StaticSETofInts ( int [ ] keys ) { a = new int [ keys . length ] ; for ( int i = 0 ; i < keys . length ; i ++ ) a [ i ] = keys [ i ] ; Arrays . sort ( a ) ; for ( int i = 1 ; i < a . length ; i ++ ) if ( a [ i ] == a [ i - 1 ] ) throw new IllegalArgumentException ( "Argument arrays contains duplicate keys." ) ; }
target:  Initializes a set of integers specified by the integer array.