docs: function (reqId, callback) {
              // PROFILING // this.$stopMeasure(req.profilingId);
  
              // Check if Flash plugin is available
              var navigator = Aria.$global.navigator;
              if (navigator.plugins && navigator.plugins.length > 0) {
                  var mime = navigator.mimeTypes, type = "application/x-shockwave-flash";
                  if (!mime || !mime[type] || !mime[type].enabledPlugin) {
                      return this.$logError(this.IO_MISSING_FLASH_PLUGIN);
                  }
              } else if (navigator.appVersion.indexOf("Mac") == -1 && Aria.$frameworkWindow.execScript) {
                  try {
                      var ActiveXObject = Aria.$global.ActiveXObject;
                      var obj = new ActiveXObject("ShockwaveFlash.ShockwaveFlash");
  
                      if (obj.activeXError) {
                          throw "ActiveXError";
                      }
                  } catch (er) {
                      return this.$logError(this.IO_MISSING_FLASH_PLUGIN);
                  }
              }
  
              // We're not ready, wait for the ready event to reissue the request, but cancel this request on timeout
              this._pending[reqId] = ariaCoreTimer.addCallback({
                  fn : this._swfTimeout,
                  scope : this,
                  args : {
                      reqId : reqId,
                      cb : callback
                  },
                  delay : this.swfTimeout
              });
  
              if (!this._transport) {
                  var swfUri = ariaCoreDownloadMgr.resolveURL('aria/resources/handlers/IO.swf');
                  // note that the flash transport does not work with Safari if the following line is present in
                  // parameters:
                  // '<param name="wmode" value="transparent"/>'
                  var obj = [
                          '<object id="xATIOSwf" type="application/x-shockwave-flash" data="',
                          swfUri,
                          '" width="1" height="1">',
                          '<param name="movie" value="' + swfUri + '" />',
                          '<param name="allowScriptAccess" value="always" />',
                          '<param name="FlashVars" value="readyCallback=' + this.$classpath + '.onXdrReady&handler='
                                  + this.$classpath + '.handleXdrResponse" />', '</object>'].join("");
  
                  var document = Aria.$frameworkWindow.document;
                  var container = document.createElement('div');
                  container.style.cssText = "position:fixed;top:-12000px;left:-12000px";
                  document.body.appendChild(container);
                  container.innerHTML = obj;
  
                  this._transport = document.getElementById("xATIOSwf");
                  this._transportContainer = container;
              }
          }