“Portrait of Greta Moll (1908) depicts a fellow-artist and a pupil of Matisse. Moll’s heirs – Oliver Williams, Margarete Green, and Iris Filmer – say that Moll, who owned the painting, turned it over in 1945 to a student of her husband, Gertrud Djamarani, fearing it would be lost or destroyed during the Allied occupation of Germany. … Instead of preserving the painting, says the complaint, Djamarani sold it in Switzerland for her own gain.”