protected boolean checkGLError() {
        try {
            Util.checkGLError();
        } catch (OpenGLException ex){
            listener.handleError("An OpenGL error has occurred!", ex);
        }
        // NOTE: Always return true since this is used in an "assert" statement
        return true;
    }
Does LWJGL display initialization in the OpenGL thread

@return true if successful, otherwise false
jme3-lwjgl/src/main/java/com/jme3/system/lwjgl/LwjglAbstractDisplay.java