Question: What was the country of origin of one of the major users of Butterfly style in 1980's hockey?
Context: The Bell P-39 Airacobra was one of the principal American fighter aircraft in service when the United States entered World War II.  The P-39 was used by the Soviet Air Force, which scored the highest number of individual kills attributed to any U.S. fighter type in the Eastern European theatre.  Other major users of the type included the Free French, the Royal Air Force, the United States Army Air Forces, and the Italian Co-Belligerent Air Force. Votty & Bowydd Quarry (sometimes historically known as Lord Quarry) is a major slate quarry in the town of Blaenau Ffestiniog, north Wales.  It was one of the major users of the Ffestiniog Railway.  It continues to produce crushed slate on a limited scale under the ownership of the nearby Llechwedd quarry. Roberto Luongo ( ; born April 4, 1979) is a Canadian professional ice hockey goaltender for the Florida Panthers of the National Hockey League (NHL).  Born in Montreal, Quebec, he is of Italian and Irish ancestry.  He employs the butterfly style of goaltending and has previously played in the NHL for the New York Islanders and the Vancouver Canucks.  Luongo is a two-time NHL Second All-Star (2004 and 2007) and a winner of the William M. Jennings Trophy for backstopping his team to the lowest goals-against average in the league (2011; with backup Cory Schneider).  He has additionally been a finalist for the Vezina Trophy as the league's best goaltender (2004, 2007 and 2011), the Lester B. Pearson Award as the top player voted by his peers (2004 and 2007) and the Hart Memorial Trophy as the league's most valuable player (2007). In ice hockey, "butterfly style" is a technique of goaltending distinguished by the goaltender guarding the lower part of the net by dropping to the knees to block attempts to score.  The butterfly style derives its name from the resemblance of the spread goal pads and hands to a butterfly's wings.  The "butterfly style" is contrasted with stand-up style, where most shots on a goal are stopped with the goaltender on their feet.  Many factors helped make it a "de facto" standard style of play today, including the popularization of the goalie mask by Jacques Plante, Vladislav Tretiak's outstanding use of the style at the 1972 Canada–USSR Summit Series, the National Hockey League (NHL) emergence of Tony Esposito in the 1970s and Patrick Roy in the 1980s, the development of lightweight materials for pads and the influence of professional goaltending coaches such as Warren Strelow, Benoit and François Allaire.  There are few who exclusively employ a stand-up style in the NHL. Maenofferen Quarry (also known as Maen Offeren Quarry) is a major slate quarry in the town of Blaenau Ffestiniog, north Wales and one of the major users of the Ffestiniog Railway.  It continues to produce crushed slate on a limited scale under the ownership of the nearby Llechwedd quarry. Glenn Henry "Mr. Goalie" Hall (born October 3, 1931) is a former professional ice hockey goaltender.  During his National Hockey League career with the Detroit Red Wings, Chicago Black Hawks, and St. Louis Blues, Hall seldom missed a game and was a consistent performer, winning the Vezina Trophy, which at the time was awarded to the goaltender on the team allowing the fewest goals against (a distinction that now results in being awarded the William M. Jennings Trophy), three times, being voted the First Team All-Star goaltender a record seven times, and winning the Calder Memorial Trophy as best rookie.  Nicknamed "Mr. Goalie", he was the first goaltender to develop and make effective use of the butterfly style of goalkeeping.  On January 1, 2017, in a ceremony prior to the Centennial Classic, Hall was part of the first group of players to be named one of the '100 Greatest NHL Players' in history.  He is the grandfather of Grant Stevenson. Yann Joseph Richard Danis (born June 21, 1981) is a Canadian professional ice hockey goaltender who is currently under contract for the Laval Rocket of the American Hockey League (AHL).  He has previously played in the National Hockey League (NHL) for the Montreal Canadiens, New York Islanders, Edmonton Oilers, and New Jersey Devils.  He plays in the butterfly style of goaltending. Patrick Jacques Roy (] ; born October 5, 1965) is a Canadian former professional ice hockey goaltender and the former head coach and vice-president of hockey operations for the Colorado Avalanche of the National Hockey League (NHL).  He is regarded as one of the greatest goaltenders of all time.  On January 27, 2017, in a ceremony during the All-Star Weekend in Los Angeles, Roy was part of the second group of players to be named one of the '100 Greatest NHL Players' in history.  Patrick is the brother of Stéphane Roy. Diphwys Casson Quarry (sometimes known as Diphwys Quarry or Diffwys Quarry) was a major slate quarry in the town of Blaenau Ffestiniog, north Wales.  It was one of the major users of the Ffestiniog Railway. Anthony James "Tony O" Esposito (born April 23, 1943) is a retired Canadian-American professional ice hockey goaltender, who played in the National Hockey League, most notably for the Chicago Black Hawks.  He was one of the pioneers of the now popular butterfly style.  Tony is the younger brother of Phil Esposito, a centre.  Both brothers had notable careers and are enshrined in the Hockey Hall of Fame.  On January 27, 2017, in a ceremony during the All-Star Weekend in Los Angeles, Esposito was part of the second group of players to be named one of the '100 Greatest NHL Players' in history.
Answer: Canada