Question: The Kellock-Taschereau Commission was appointed by a prime minister who served how long in office?

<P0-S0> The Kellock–Taschereau Commission (officially the Royal Commission to Investigate the Facts Relating to and the Circumstances Surrounding the Communication, by Public Officials and Other Persons in Positions of Trust of Secret and Confidential Information to Agents of a Foreign Power) was a royal commission appointed by Prime Minister William Lyon Mackenzie King on behalf of the Government of Canada under Order in Council PC 411 on February 5, 1946. <SEP> <P1-S0> Bouasone Bouphavanh (born 3 June 1954) was Prime Minister of Laos from 2006 to 2010. <P1-S1>  He was officially appointed to the office by the National Assembly of Laos on June 8, 2006, during a major government reshuffle. <P1-S2>  He replaced Bounnhang Vorachith who became vice president. <P1-S3>  Bouasone had previously served as first deputy prime minister since October 3, 2003. <P1-S4>  Before that, he was third deputy prime minister and was president of the State Planning Committee. <P1-S5>  He ranks seventh in the Politburo. <P1-S6>  He was replaced as Prime Minister on 23 December 2010 by Thongsing Thammavong. <P1-S7>  Now,Bouasone Bouphavanh currently serves as head of the Lao Party Central Committee's Commission for Economic Development Strategy Research. <SEP> <P2-S0> The Swedish constitution of 1974 allows the Prime Minister of Sweden to appoint one of the Ministers in the cabinet as Deputy Prime Minister ("biträdande statsminister", also unofficially known as "vice statsminister", "Vice Prime Minister"), in case the Prime Minister for some reason is prevented from performing his or her duties. <P2-S1>  However, if a Deputy Prime Minister has not been appointed, the Minister in the cabinet who has served the longest time (and if there are several with equal experience the one who is oldest) takes over as head of government. <P2-S2>  Note that the person acting as Prime Minister does not do so on a permanent basis: if a Prime Minister dies, resigns or loses a vote of confidence in the Riksdag, the Speaker of the Riksdag will then confer with the parties of the Riksdag and propose a new Prime Minister, who must be tolerated by a majority of the Riksdag. <P2-S3>  If the Prime Minister has resigned or lost a vote of confidence, he or she will remain the head of a government "ad interim" until the new Prime Minister assumes his or her office. <P2-S4>  The only case where the governmental line of succession becomes relevant is when the Prime Minister dies (upon which the person next in the line of succession serves as the head of a government "ad interim") or when the Prime Minister is on leave or for any other reason incapable of serving, but still remains in office. <P2-S5>  This might be compared to the Presidential line of succession in the United States, where the person next in line assumes the Presidency throughout the remainder of the term if the President dies, resigns or is impeached. <SEP> <P3-S0> William Lyon Mackenzie King (December 17, 1874 – July 22, 1950), also commonly known as Mackenzie King, was the dominant Canadian political leader, as the Prime Minister of Canada, from the 1920s through the 1940s. <P3-S1>  He served as the tenth Prime Minister of Canada in 1921–1926, 1926–1930 and 1935–1948. <P3-S2>  He is best known for his leadership of Canada throughout the Second World War (1939–1945) when he mobilized Canadian money, supplies and volunteers to support Britain while boosting the economy and maintaining home front morale. <P3-S3>  Trained in law and social work, he was keenly interested in the human condition (as a boy, his motto was "Help those that cannot help themselves"), and played a major role in laying the foundations of the Canadian welfare state. <P3-S4>  A Liberal with 21 years and 154 days in office, he was the longest-serving prime minister in Canadian history.