ClientCanvas clientCanvas = new ClientCanvas( shell, SWT.NONE );
ClientDrawListener drawListener = mock( ClientDrawListener.class );
clientCanvas.addClientDrawListener( drawListener );
ClientCanvasOperator operator = new ClientCanvasOperator( clientCanvas );
environment.newRequest();
JsonObject drawings = new JsonObject();
drawings.add( ClientCanvasOperator.DRAWINGS_PROPERTY, JsonValue.valueOf( ClientCanvasTestUtil.createDrawings( 1 ) ) );
environment.dispatchNotify( ClientCanvasOperator.DRAWING_EVENT, drawings );
operator.handleNotify( clientCanvas, ClientCanvasOperator.DRAWING_EVENT, drawings );
DrawingsCache cache = clientCanvas.getAdapter( DrawingsCache.class );