comefrom: <awangdev>Evaluate Reverse Polish Notation_1.java
code: private boolean isOperator(String s) {
  
          if (s.length() != 1) return false;
          char c = s.charAt(0);
          return c == '+' || c == '-' || c == '/' || c == '*';
      }
masked: private boolean var_0 ( String var_2 ) {
    if ( var_2 . length ( ) != 1 ) return false ;
    char var_7 = var_2 . charAt ( 0 ) ;
    return var_7 == '+' || var_7 == '-' || var_7 == '/' || var_7 == '*' ;
  }
  