code: private void bindEvents() {
  		visibilityToggle.addClickHandler(new ClickHandler() {
  
  			public void onClick(ClickEvent event) {
  				if (visibilityToggle.isEnabled()) {
  					presenter.toggleLayerVisibility();
  					visibilityToggle.setEnabled(true); // Works because JavaScript is single threaded...
  				}
  			}
  		});
  	}
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