title: Calling varargs method mixing elements and array of elements does not work
body: <p>I have a method with the following signature:</p>
  
  <pre><code>public void foo(String... params);
  </code></pre>
  
  <p>So all of these calls are valid:</p>
  
  <pre><code>foo("Peter", "John");
  foo(new String[] { "Peter", "John" });
  </code></pre>
  
  <p>But why is this one not valid?</p>
  
  <pre><code>foo("Peter", new String[] { "John" });
  </code></pre>