comefrom: <awangdev>218. The Skyline Problem_2.java
code: private boolean isInvalid(int[][] buildings) {
  
          return buildings == null || buildings.length == 0 || buildings[0] == null || buildings[0].length == 0;
      }
masked: private boolean var_0 ( int [ ] [ ] var_1 ) {
    return var_1 == null || var_1 . length == 0 || var_1 [ 0 ] == null || var_1 [ 0 ] . length == 0 ;
  }
  