This asymmetrical element nods both to the location of a lone hawthorn tree planted in the original courtyard in the 1960s, while simultaneously serving as a drainage system of rain and snow that Buffalo is famed for.[15] The Seymour H. Knox Building now includes rooms where visitors can participate in art workshops themselves, the so-called Creative Commons, which represents the first cooperation of the Lego Foundation with a museum.[needs update] This vote follows AKG Workers United filing unfair labor practice charges against the museum, accusing its leadership of "heightening surveillance of employees and re-enforcing workplace rules in direct response to unionization efforts."[24] The gallery's collection includes works spanning Impressionistic and Post-Impressionistic styles by artists of the nineteenth century such as Paul Gauguin, Edgar Degas, Berthe Morisot, Claude Monet, and Vincent van Gogh.Revolutionary styles from the early twentieth century such as abstraction, cubism, surrealism, and constructivism are represented in works by artists like Pablo Picasso, Georges Braque, Jean Metzinger, Albert Gleizes, Henri Matisse, André Derain, Joan Miró, Piet Mondrian, Giacomo Balla, Sonia Delaunay, Georgia O'Keeffe, Amedeo Modigliani, and Alexander Rodchenko.[25] That movement is widely represented in the collection with works by artists including Arshile Gorky, Jackson Pollock, Joan Mitchell, Franz Kline, Robert Motherwell, Adolph Gottlieb, and Helen Frankenthaler.[28] Their contemporary collection includes pieces by artists such as Cory Arcangel, Tony Conrad, Mark Bradford, Nick Cave, Simone Leigh, Georg Baselitz, John Connell, and Per Kirkeby.Some of the most notable, from the past and the present, include: In 2007, the Albright–Knox Art Gallery sold a Roman-era bronze sculpture, Artemis and the Stag, that was auctioned at Sotheby's New York on June 7, 2007, and brought $28.6 million.In February 2007, when the list of works to be deaccessioned was made public, Albright-Knox Director Louis Grachos defined the ancient sculpture as falling outside the institution's historical "core mission" of "acquiring and exhibiting art of the present."This definition made public critics wonder whether the position at the Gallery of "William Hogarth's Lady's Last Stake or Sir Joshua Reynolds' Cupid as a Link Boy were secure.[39] In 2016, Los Angeles financier Jeffrey Gundlach contributed $42.5 million, the largest donation from a single individual in the museum's history.