code: protected void renderInputTagValue(FacesContext context, ResponseWriter rw,
  			SelectBooleanCheckbox selectBooleanCheckbox) throws IOException {
  		String v = getValue2Render(context, selectBooleanCheckbox);
  		if (v != null && "true".equals(v)) {
  			rw.writeAttribute("checked", v, null);
  		}
  	}
docs: Renders the value of the input tag. This method is protected in order to
  allow third-party frameworks to derive from it.
  
  @param context
  the FacesContext
  @param rw
  the response writer
  @param selectBooleanCheckbox
  the component to render
  @throws IOException
  may be thrown by the response writer