output: #fixed code
                                  public static boolean isLeopard() {
          return SystemInfo.isMacOSX() && SystemInfo.getOSVersion().startsWith("10.5");
      }
input: #vulnerable code 
                                  public static boolean isLeopard() {
          return isMac() && getOsVersion().startsWith("10.5");
      } 
                              #location 2 
                              #vulnerability type NULL_DEREFERENCE