message: Set gui_mode last when applying a preset.
  Otherwise we will do a breath with the old configuration!
  GPC: gui-mode-last
diff: @@ -124,12 +124,15 @@ Intended TV: {intended_tv} ml
  sec_per_breath = 60 / rr
  ie_ratio = inspiratory_time / sec_per_breath
  vars = {
  - "gui_mode": VentMode_PRESSURE_CONTROL,
  "gui_bpm": rr,
  "gui_ie_ratio": round(ie_ratio, 2),
  "gui_pip": bap + delta_inspiratory_pressure,
  "gui_peep": bap,
  # TODO: FiO2 not currently supported.
  + # It's important to set gui_mode last. Otherwise we'll start breathing
  + # immediately, with whatever the old parameters happen to be. (Python3
  + # dicts have consistent ordering.)
  + "gui_mode": VentMode_PRESSURE_CONTROL,
  }
  return Preset(f"covent_pc_{test_num}", desc, vars)
  