         // Put teardown code here. This method is called after the invocation of each test method in the class.
         super.tearDown()
     }
-    
+
+    let jsTestingMessageHandlerString = "jsTesting"
     let startTimeMessageString = "startTime"
     let firstSectionAppearedMessageString = "firstSectionAppeared"
     

                let tenMillisecondPollingJS = """
                const checkFirstSectionPresence = () => {
                   if(document.querySelector('#section_heading_and_content_block_0')){
                       window.webkit.messageHandlers.jsTesting.postMessage('\(self.firstSectionAppearedMessageString)')
                   }else{
                       setTimeout(checkFirstSectionPresence, 10 )
                   }

            // Configure the WKUserContentController used by the web view controller - easy way to attach testing JS while
            // keeping all existing JS in place.
            webVC?.wkUserContentControllerTestingConfigurationBlock = { userContentController in
                userContentController.add(self, name: self.jsTestingMessageHandlerString)
                
                // This message will be sent as soon as the web view inflates the DOM of the index.html (before our
                // sections are injected).
                let startTimeJS = "window.webkit.messageHandlers.\(self.jsTestingMessageHandlerString).postMessage('\(self.startTimeMessageString)')"
                userContentController.addUserScript(
                    WKUserScript.init(source: startTimeJS, injectionTime: .atDocumentEnd, forMainFrameOnly: true)
                )
