In what film were the two principal male characters played by actors called Dustin and Justin?

Kramer vs. Kramer is a 1979 American drama film adapted by Robert Benton from the novel by Avery Corman, and directed by Benton. The film tells the story of a couple's divorce and its impact on everyone involved, including the couple's young son. It received five Academy Awards at the 52nd Academy Awards in 1980, in the categories of Best Picture, Best Director, Best Adapted Screenplay, Best Actor, and Best Supporting Actress.

Ted Kramer (Dustin Hoffman) is a workaholic advertising executive who has just been assigned a new and very important account. Ted arrives home and shares the good news with his wife Joanna (Meryl Streep) only to find that she is leaving him. Saying that she needs to find herself, she leaves Ted to raise their son Billy (Justin Henry) by himself. Ted and Billy initially resent one another as Ted no longer has time to carry his increased workload and Billy misses his mother's love and attention. After months of unrest, Ted and Billy learn to cope and gradually bond as father and son.