code: @Override
  	protected void validateComponent(final List<Diagnostic> diags) {
  		super.validateComponent(diags);
  
  		WComponent visibleDialog = getVisible();
  
  		if (visibleDialog != null) {
  			visibleDialog.validate(diags);
  		}
  	}
docs: Since none of the children are visible to standard processing, validateComponent has been overridden so that the
  visible card is processed.
  
  @param diags the list to add validation diagnostics to.