code: function injectStyleTag(cssContents) {
      if (styleTag == null) {
          // Try to find a style tag with the `data-aphrodite` attribute first.
          styleTag = document.querySelector("style[data-aphrodite]");
  
          // If that doesn't work, generate a new style tag.
          if (styleTag == null) {
              // Taken from
              // http://stackoverflow.com/questions/524696/how-to-create-a-style-tag-with-javascript
              var head = document.head || document.getElementsByTagName('head')[0];
              styleTag = document.createElement('style');
  
              styleTag.type = 'text/css';
              styleTag.setAttribute("data-aphrodite", "");
              head.appendChild(styleTag);
          }
      }
  
      if (styleTag.styleSheet) {
          styleTag.styleSheet.cssText += cssContents;
      } else {
          styleTag.appendChild(document.createTextNode(cssContents));
      }
  }
docs: Inject a string of styles into a <style> tag in the head of the document. This will automatically create a style tag and then continue to use it for multiple injections. It will also use a style tag with the `data-aphrodite` tag on it if that exists in the DOM. This could be used for e.g. reusing the same style tag that server-side rendering inserts.