adequate substitution to defeat loose leaf prices increases, then it should be included in the relevant product market, because of its ability to constrain prices and maintain a competitive marketplace. See, e.g., Cardinal Health, 12 F.Supp.2d at 46 (“In other words, when one product is a reasonable substitute for the other, it is to be included in the same relevant product market even though the products themselves are not the same. A product is construed to be a ‘reasonable substitute for another when the demand for it increases in response to an increase in the price for the other.’ ”). Whether moist snuff tobacco is similar in character or use to loose leaf tobacco may be termed “functional interchangeability.” See, e.g., E.I. du Pont de Nemours, 351 U.S. at 399, 76 S.Ct. 994 (<HOLDING>); United States v. Archer-Daniels-Midland Co.,
recognizing flexible due diligence standard for determining whether service of process on foreign national was timely recognizing conflict between circuits recognizing functional interchangeability between cellophane and other flexible wrappings recognizing distinction between tolling and estoppel recognizing difference between tolling and equitable estoppel