title: Is there java.util.concurrent equivalent for WeakHashMap?
body: <p>Can the following piece of code be rewritten w/o using <code>Collections.synchronizedMap()</code> yet maintaining correctness at concurrency? </p>
  
  <pre><code>Collections.synchronizedMap(new WeakHashMap&lt;Class, Object&gt;());
  </code></pre>
  
  <p>i.e. is there something from java.util.concurrent one can use instead? Note that merely replacing with </p>
  
  <pre><code>new ConcurrentHashMap&lt;Class, Object&gt;(new WeakHashMap&lt;Class, Object&gt;()));
  </code></pre>
  
  <p>obviously won't work</p>