The conversation between human and AI assistant.
[|Human|] Given a reference text about Justice League Dark, tell me who the main actors are and what roles they played.
[|AI|] The main actors in Justice League Dark were Matt Ryan and Jason O'Mara. In the film, Matt Ryan is John Constantine and Jason O'Mara is Batman.
[|Human|] 
Given a reference text about Justice League Dark, tell me who the main actors are and what roles they played.