code: public Boolean isTopmostElement(By by) {
  		if (!isTopmostElementCheckApplicable(by)) {
  			return null;
  		}
  		WebElement topmostElement = findTopmostElement(by);
  		WebElement element = findElement(by);
  		return element.equals(topmostElement);
  	}
docs: Checks if an element is the topmost, i.e. not covered by any other element.
  
  @param by
  the {@link By} used to locate the element.
  @throws WebElementException
  if the element cannot be located or moved into the viewport.
  @return {@code true} if the element is the topmost element, {@code false}
  if not or {@code null} if the topmostElementCheck is not applicable.