title: What does Mockito.anyLong() do?
body: <p>I have to test a method which takes a Long as argument. I have to test it for any value of the Long and also in case it's null. Does Mockito.anyLong() automatically test both cases? null and any value of the Long? Or randomly picks up a value between any long value and null?
  Considering that these are the docs about anyLong():</p>
  
  <blockquote>
    <p>anyLong</p>
    
    <p>public static long anyLong()</p>
  
  <pre><code>any long, Long or null.
  
  See examples in javadoc for Matchers class
  
  Returns:
      0.
  </code></pre>
  </blockquote>
  
  <p>Thanks in advance.</p>