It’s a sun-drenched Sunday in Chicago’s Washington Park on the northern lawn of the DuSable Museum, where the leaves of large oak trees offer a comforting shade to a grassy hollow at the foot of 18th-century German writer Gotthold Lessing’s statue. The South Side park is the perfect place for a picnic, space to daydream or a rejuvenating yoga session with Aya-Nikole Cook.