Question: Who now owns the company that was headed by Robert Leo "Bob" Hulseman until 2006?
Context: Robert Leo Kistler (born March 4, 1925) was an American politician in the state of Iowa.  Kistler was born in Osceola, Iowa.  He attended Simpson College, Drake University and University of Iowa, and was an educator.  He served in the Iowa House of Representatives from 1989 to 1995, as a Republican. Robert Leo Sheppard (October 20, 1910 – July 11, 2010) was the long-time public address announcer for numerous New York area college and professional sports teams, in particular the New York Yankees of Major League Baseball (1951–2007), and the New York Giants (1956–2006) of the National Football League. Robert Leo "Bob" Hulseman (April 5, 1932 – December 21, 2016) was an American businessman and entrepreneur who was best known as the inventor of the red solo cup, which is produced by his family's company, Solo Cup Company.  He also co-designed the Traveler Lid, which prevents foam from hot beverages such as lattes and cappuccinos from touching the drinker's nose, now widely used by Starbucks and other brands.  Hulseman joined the staff of The Solo Cup Company, which had been founded in 1936 by his father Leo Hulseman, when he was 18 years old.  Hulseman spent more than 60 years at the Solo Cup Company, including as the company's President and CEO from 1980 until 2006. Robert Leo Heleringer, known as Bob Heleringer (born May 14, 1951, in Louisville, Kentucky) is a Republican lawyer and figure in the horse breeding industry who from 1980 to 2002 held the District 33 seat in the Kentucky House of Representatives, based in suburban Jefferson County. Robert Leo Patrick "Grandpappy" Dove (February 21, 1921 – April 19, 2006) was an American football player and coach.  He played college football at the University of Notre Dame and professionally for eight seasons in the National Football League (NFL).  Following his retirement as a player, Dove embarked on a 37-year coaching career at the professional and collegiate levels.  He was inducted into the College Football Hall of Fame as a player in 2002. Robert Leo Donovan (20 June 1899, in Dublin – 26 February 1932, in Dublin) was an Irish cricketer.  A left-handed batsman and left-arm medium pace bowler, he played just once for the Ireland cricket team, a first-class match against Scotland in August 1921, scoring three runs in the only innings, and not bowling. Robert Leo Hackett (January 31, 1915 – June 7, 1976) was an American jazz musician who played trumpet, cornet, and guitar with the bands of Glenn Miller and Benny Goodman in the late 1930s and early 1940s.  Hackett is probably best known for being the featured soloist on some of the "Jackie Gleason" mood music albums during the 1950s. Robert Leo Kieffer (September 11, 1930 – August 12, 2017) was an American businessperson and politician from Maine.  Kieffer, a Republican, served in the Maine State Senate from 1992-2000, representing his residence in Caribou, Maine as well as much of Aroostook County.  He replaced fellow Republican Donald Collins, who did not seek re-election.  Prior to serving in the State Senate, Kieffer served five years on the Caribou Town Council, including a stint as mayor (1991-1992).  In February 1997, Kieffer was named legislator of the year by the Economic Development Council of Maine.  From 1996-1998, Kieffer served as Assistant Senate Minority Leader. Solo Cup Company is an American manufacturer of disposable consumer products including beverage cups, disposable plates and bowls.  Solo Cup Company is located in Lake Forest, Illinois, and in 2006 had sales of $2.4 billion.  On May 4, 2012, Solo Cup Company was acquired by Dart Container. Robert Leo Prestel (born February 11, 1936) is an American intelligence official and mathematician who was Deputy Director of the National Security Agency from 1990 to 1994, during which time he was the highest ranking civilian in the agency.  Prestel joined the NSA in 1962 and held many positions prior to being appointed as deputy director, including Director of Education and Training from Deputy Director for Research and Engineering.  Among other positions Prestel has served in include trustee for the Institute for Defense Analyses and on the Board of Directors of WJ Communications.  He currently serves as trustee emeritus of Institute for Defense Analyses.
Answer: Dart Container