comefrom: <qiyuangong>1323_Maximum_69_Number_1.java
code: public int maximum69Number (int num) {
          return Integer.valueOf(String.valueOf(num).replaceFirst("6", "9"));
      }
masked: public int sample_funcname ( int var_0 ) {
    return Integer . valueOf ( String . valueOf ( var_0 ) . replaceFirst ( "6" , "9" ) ) ;
  }
  