title: How to apply waitForExist() on two selector simultaneously in webDriverIO
body: <p>Currently, I am upgrading the WebDriverIo version from 4 to 5 wherein one of the existing tests we are applying waitForExist on two selectors simultaneously. In v4 it's like this <code>.waitForExist(selector + loadingSelector, null, true)</code> But in V5 waitForExist chaining to selector and therefore I've refactored this to <code>await (sel1+loadingSelector).waitForExist(0,true,null);</code> but this throwing error `TypeError: (selector + loadingSelector).waitForExist is not a function</p>
  <p>Here is my bit of command code:</p>
  <pre><code>addIdeCommand('ideOpenFolder', async function (folder, treeCls, fuzzy) {
      var sel1 =await browser.$(sel1);
      var loadSelector = await browser.$(sel2);
      
  
          await sel1.waitForDisplayed();
          // Wait for the loading icon to disappear (true = not exists)
         **await (selector+loadSelector).waitForExist(0,true,null);**
          await this.waitUntil(async function () {
              //something
          });
  });
  </code></pre>
  <p>Can someone please help me with how to apply waitForExisting() on multiple selectors at the same time?</p>