Draw the actions so that they can be inspected for accuracy.

def draw_actions(self):
    """Draw the actions so that they can be inspected for accuracy."""
    now = time.time()
    for act in self._past_actions:
      if act.pos and now < act.deadline:
        remain = (act.deadline - now) / (act.deadline - act.time)
        if isinstance(act.pos, point.Point):
          size = remain / 3
          self.all_surfs(_Surface.draw_circle, act.color, act.pos, size, 1)
        else:
          # Fade with alpha would be nice, but doesn't seem to work.
          self.all_surfs(_Surface.draw_rect, act.color, act.pos, 1)