comefrom: <awangdev>O(1) Check Power of 2_1.java
code: public boolean checkPowerOf2(int n) {
          if (n <= 0) {
              return false;
          }
          return (n & (n - 1)) == 0;
      }
masked: public boolean var_0 ( int var_1 ) {
    if ( var_1 <= 0 ) {
      return false ;
    }
    return ( var_1 & ( var_1 - 1 ) ) == 0 ;
  }
  