Q:Information:  - Vincent Condol "Vince" Gray (born November 8, 1942) is an American politician who served as the seventh Mayor of the District of Columbia. He served one term, from 2011 to 2015, losing his bid for reelection in the Democratic primary to D.C. City Council member Muriel Bowser. Bowser would go on to win the 2014 election. Prior to his inauguration as mayor in January 2011, Gray served as Chairman of the Council of the District of Columbia, and as Councilmember for Ward 7. In the 1990s he also served as director of the DC Department of Human Services. In June 2016, he defeated incumbent Yvette Alexander in the Democratic primary for the council seat he previously held in Ward 7.  - Adrian Malik Fenty (born December 6, 1970) is an American politician who served as the sixth mayor of the District of Columbia. He served one term, from 2007 to 2011, losing his bid for reelection at the primary level to Democrat Vincent C. Gray. Though Fenty won the Republican mayoral primary as a write-in candidate, he declined the Republican nomination and said he would likely not seek elected office again. Gray went on to win the general election for Mayor in the largely Democratic District.  - The Washington , D.C. mayoral election of 2010 took place on Tuesday , November 2 , 2010 . The primary elections occurred on September 14 , 2010 . Vincent Gray won the general election by a wide margin , although many voters wrote in incumbent Mayor Adrian Fenty , whom Gray defeated in the primary .    What entity does 'washington' has the relation 'office contested' with?
A:
mayor of the district of columbia