comefrom: <gouthampradhan>backtracking_PermutationsII_1.java
code: private void swap(int[] a, int i, int j) {
      int tmp = a[i];
      a[i] = a[j];
      a[j] = tmp;
    }
masked: private void var_0 ( int [ ] var_1 , int var_2 , int var_3 ) {
    int var_4 = var_1 [ var_2 ] ;
    var_1 [ var_2 ] = var_1 [ var_3 ] ;
    var_1 [ var_3 ] = var_4 ;
  }
  