A deme's population was steady at 6347 before it changed to 8737 7936.2611 generations ago, maintaining that number to the present.
time_units: generations
demes:
  - name: A
    start_time: .inf
    epochs:
      - start_size: 6347
        end_time: 7936.2611
      - start_size: 8737
        end_time: 0