title: GWT client - Uncaught TypeError: Cannot read property 'clear_31_g$' of undefined
body: <p>I am new to GWT and trying to create a small application. I am currently assembling a small framework for the app, a generic layout handler, etc. This may not be the last problem I will bump into, but I just cannot find any solution to this on google.</p>
  
  <p>So I have a class type, which return me Composites. Also, I have another one, which stores these kind of classes in Stack (I also tried Vector, I thought maybe GWT has issues with it). It didn't matter. If I call the .clear method on the Stack, I have the aforementioned error in the inspection menu of Chrome:
  Uncaught TypeError: Cannot read property 'clear_31_g$' of undefined</p>
  
  <p>Like if GWT does not know, how to convert this method to javascript or what? Do you know what is the problem here?</p>
  
  <p>eclipse neon, Java 7 setting on Java SDK 1.8 (maybe this?), GWT 2.7.0 and App Engine 1.9.34</p>
  
  <p>Thanks!</p>
  
  <p>edit1: I also found the page, which contains the emulated JRE classes' list (<a href="http://www.gwtproject.org/doc/latest/RefJreEmulation.html" rel="nofollow">http://www.gwtproject.org/doc/latest/RefJreEmulation.html</a>) with all supported methods. Now I see, that clear is not on that list for Stack, but empty does and that gives me the same error. :-/</p>