<awangdev>4Sum_1.java
private String buildKey(List<Integer> list) {

        StringBuffer sb = new StringBuffer();
        for (int num : list) sb.append(num + "@");
        return sb.toString();
    }
private String var_0 ( List < Integer > var_3 ) {
  StringBuffer var_5 = new StringBuffer ( ) ;
  for ( int var_6 : var_3 ) var_5 . append ( var_6 + "@" ) ;
  return var_5 . toString ( ) ;
}
