docs: function removeLibraries(iframe) {
          var idx;
          var contentDocument;
          var scriptNodes, scriptNode;
  
          contentDocument = W.getIFrameDocument(iframe);
  
          // Old IEs do not have getElementsByClassName.
          scriptNodes = W.getElementsByClassName(contentDocument, 'injectedlib',
                                                 'script');
  
          // It was. To check.
          // scriptNodes = contentDocument.getElementsByClassName('injectedlib');
          for (idx = 0; idx < scriptNodes.length; idx++) {
              scriptNode = scriptNodes[idx];
              scriptNode.parentNode.removeChild(scriptNode);
          }
      }