title: JavaFX - Methods creating a new BooleanExpression cause memory leaks
body: <p>I have just noticed that methods not(), and(), or() from both classes BooleanExpression and Bindings create a new BooleanExpression which probably stays in memory even if it does not have any reference.</p>
  
  <pre><code>myBool = new SimpleBooleanProperty();
   for (int i = 0; i &lt; 10000000; i++) {
   myBool.not();
  }
  </code></pre>
  
  <p>Aforementioned code creates about 530 MB which stay in memory until the 'myBool' variable is dereferenced (and cleaned).</p>
  
  <p>Is this a bug or normal behavior? If so, is there any way how to clean the memory without loosing 'myBool' variable?</p>