title: Passing Optional.absent() values to methods concisely
body: <p>One problem with using Guava's <code>Optional</code> type as arguments of methods is that you can't simply write</p>
  
  <pre><code>// method declaration
  public void foo(Optional&lt;String&gt; arg);
  
  // compiler error
  foo(Optional.absent());
  </code></pre>
  
  <p>due to type inference failing but instead have to add the type explicitly:</p>
  
  <pre><code>// real method call
  foo(Optional.&lt;String&gt; absent());
  </code></pre>
  
  <p>How can I avoid it?</p>