docs: function(styles) {
      var serialized = '';
      for (var styleName in styles) {
        if (!styles.hasOwnProperty(styleName)) {
          continue;
        }
        var styleValue = styles[styleName];
        if ("production" !== process.env.NODE_ENV) {
          warnValidStyle(styleName, styleValue);
        }
        if (styleValue != null) {
          serialized += processStyleName(styleName) + ':';
          serialized += dangerousStyleValue(styleName, styleValue) + ';';
        }
      }
      return serialized || null;
    }