title: Null pointer exception while retrieving all instances of a class with the BIMserver Java client
body: <p>I am very new to BIMserver and I am trying to get instances of a specific class of the IFC I have checked in, using the Java client library and IfcModelInterface.</p>
  
  <p><strong>Here is the piece of code :</strong></p>
  
  <pre><code>IfcModelInterface model = client.getModel(project, project.getLastRevisionId(),false, true,true);
  Collection&lt;IfcProduct&gt; products = model.getAllWithSubTypes(IfcProduct.class);
  </code></pre>
  
  <p>The call to <code>getAllWithSubtypes</code> results in a null pointer exception.
  When I debug it goes to the class where :</p>
  
  <pre><code>public &lt;T extends IdEObject&gt; List&lt;T&gt; getAllWithSubTypes(EClass eClass) {
      if (!loadedClasses.contains(eClass.getName()) &amp;&amp; modelState != ModelState.FULLY_LOADED) {
  </code></pre>
  
  <p>eClass is null and hence I get an exception, I don't understand why?</p>