title: Map putAll overrides or adds?
body: <p>When i use the <code>.putAll()</code> will another <code>.putAll()</code> override the content of the map?
  Will my map contain SomeOfMyObjects and SomeOfMyObjects?</p>
  
  <pre><code>Map&lt;MyObject&gt; blah = new HashMap&lt;&gt;();
  blah.putAll('SomeOfMyObjects')
  blah.putAll('SomeOfMyObjects')
  </code></pre>
  
  <p>Thanks!</p>