code: public WebElementFinder displayed(final Boolean theDisplayed) {
  		Fields fields = new Fields(this);
  		fields.displayed = theDisplayed;
  		return new WebElementFinder(fields);
  	}
docs: Creates an new {@link WebElementFinder} based on this {@link WebElementFinder} restricting the displayed status of
  elements.
  
  @param theDisplayed
  {@code true} if elements must be displayed, {@code false} if elements must not be displayed
  @return the new {@link WebElementFinder} instance
  @see WebElement#isDisplayed()