title: OPA matcher for sap.m.MessageToast with expected content
body: <p>I have a similar question as <a href="https://stackoverflow.com/questions/31425828/opa-matcher-for-sap-m-messagetoast-show-call">this</a></p>
  
  <p>But, how can I check the content of <code>sap.m.MessageToast</code> is correct or not?</p>
  
  <pre><code>iShouldSeeAToastMessage : function(sText) {
      return this.waitFor({
          pollingInterval : 100,
          check : function() {
              return !!sap.ui.test.Opa5.getJQuery()(".sapMMessageToast").length;
          },
          success : function (oMessage) {
              strictEqual(oMessage[0].getText(), sText, "The message display correctly");
          },
          errorMessage : "No Toast message detected!"
      });
  }
  </code></pre>
  
  <p>I tried the above code. But, maybe, the <code>success</code> callback returns no object. So, I got the error message: <em>Cannot read property '0' of null</em></p>
  
  <p>=======================================</p>
  
  <p>I tried the following code. The testcase is passed. But, I am not sure it is a correct test code.</p>
  
  <pre><code>success : function () {
      strictEqual(sap.ui.test.Opa5.getJQuery()(".sapMMessageToast")[0].innerHTML, sText, "The message display correctly");
  }
  </code></pre>