title: Java - Map allowing null values/keys and not thread safe
body: <p>I'm looking for an implementation of the Map interface with the following requirements :</p>
  
  <ul>
  <li>Not thread-safe</li>
  <li>Not allowing null values and null keys</li>
  <li>In the JDK</li>
  </ul>
  
  <p>Do you know of one ?</p>
  
  <p><strong>Java 6</strong></p>