A, the owner of a Maryland restaurant named "Burger Mansion" sued B, the owner of a Virginia restaurant with the same name. A filed a complaint in Maryland federal court seeking $50,00 in damages and alleging that B's use of "Burger Mansion" infringed A's trademark in violation of federal trademark laws. B filed an answer and began taking discovery. Nearly a year into the lawsuit, B moved to dismiss the lawsuit for lack of subject matter jurisdiction