function createDangerousStringForStyles(styles) {
    {
      var serialized = '';
      var delimiter = '';

      for (var styleName in styles) {
        if (!styles.hasOwnProperty(styleName)) {
          continue;
        }

        var styleValue = styles[styleName];

        if (styleValue != null) {
          var isCustomProperty = styleName.indexOf('--') === 0;
          serialized += delimiter + (isCustomProperty ? styleName : hyphenateStyleName(styleName)) + ':';
          serialized += dangerousStyleValue(styleName, styleValue, isCustomProperty);
          delimiter = ';';
        }
      }

      return serialized || null;
    }
  }
This creates a string that is expected to be equivalent to the style
attribute generated by server-side rendering. It by-passes warnings and
security checks so it's not safe to use this value for anything other than
comparison. It is only used in DEV for SSR validation.