sentences:  One such example sold by BK's European arm of the company is a larger version of the sandwich called the Big King XXL, based on the company's Whopper sandwich.The Big King XXL is part of a line of larger double cheeseburgers known as the BK XXL line; the XXL line was the center of controversy over product health standards and advertising in Spain when first introduced.There is also a chicken variant of the sandwich in the United States and Canada.