title: Please elaborate difference between assertArrayHasKey() and assertEquals() in the below code
body: <p>I was reading a Unit Test and it contains these two functions
  assertArrayHasKey() and assertEquals()</p>
  
  <p>Please explain the difference between them by sitting in the context of below code.</p>
  
  <pre><code>// Test all basic required params were set
      $options = $getReportInstance-&gt;getOptions();
      $this-&gt;assertArrayHasKey('AWSAccessKeyId', $options, "Option AWSAccessKeyId doesn't exit");
      $this-&gt;assertEquals(self::APP_ACCESS_KEY, $options['AWSAccessKeyId'], "AWSAccessKeyId was not set correctly!");
      $this-&gt;assertArrayHasKey('SignatureMethod', $options, "Option SignatureMethod doesn't exist");
      $this-&gt;assertEquals(
          self::SIGNATURE_METHOD,
          $options['SignatureMethod'],
          "SignatureMethod was not set correctly!"
      );
  </code></pre>