title: How do I leverage generics and check my parameters in this usage of addItem?
body: <p>So I'm getting the good ol' <code>unchecked call to addItem(E)</code> for a JComboBox.  I'm familiar with the common case, but the combobox is in a list processed functionally though and the solution eludes me.  Stripped down code sample:</p>
  
  <pre><code>public static Boolean final test(final List&lt;JComboBox&gt; comboboxList) {
    final List&lt;String&gt; stuff=new ArrayList&lt;&gt;();
    // stuff gets stuffed with stuff here
    comboboxList.forEach((JComboBox combobox) -&gt; {
      combobox.removeAllItems();
      stuff.forEach((contents) -&gt; {
        combobox.addItem(contents);
      });
    });
  }
  </code></pre>
  
  <p>The comboboxes in the List being passed in are all declared as <code>&lt;String&gt;</code>, but that doesn't seem to help the addItem in the forEach.  Seems like I should declare it in the forEach, but I've been unable to find a valid syntax for doing so.</p>