title: What are the reasons why Map.get(Object key) is not (fully) generic
body: <p>What are the reasons behind the decision to not have a fully generic get method 
  in the interface of <a href="http://java.sun.com/javase/6/docs/api/java/util/Map.html#get(java.lang.Object)" rel="noreferrer"><code>java.util.Map&lt;K, V&gt;</code></a>.</p>
  
  <p>To clarify the question, the signature of the method is </p>
  
  <p><code>V get(Object key)</code></p>
  
  <p>instead of </p>
  
  <p><code>V get(K key)</code></p>
  
  <p>and I'm wondering why (same thing for <code>remove, containsKey, containsValue</code>).</p>