anchor.diff:              buffer.writeCharCode($backslash);
               buffer.writeCharCode($double_quote);
             } else if (includesSingleQuote) {
  -            _visitString(string, forceDoubleQuote: true);
  +            _visitQuotedString(string, forceDoubleQuote: true);
               return;
             } else {
               includesDoubleQuote = true;
  
positive.code:       _buffer.writeCharCode(quote);
        _buffer.write(buffer);
        _buffer.writeCharCode(quote);
      }
    }
  
  
negative.code:           if (forceDoubleQuote) {
              buffer.writeCharCode($single_quote);
            } else if (includesDoubleQuote) {
              _visitQuotedString(string, forceDoubleQuote: true);
              return;
            } else {
              includesSingleQuote = true;
  