def do(actor, targets)
    #Acceleration will be limited by elapsed time.
    pull_force = delta
    targets.each do |target|
      #Angle from target to actor is also angle of pull force (opposite of that for push).
      pull_angle = Utility.find_angle(target.location, actor.location)
      #Apply the force to the creature's movement vector.
      target.vector += Vector.new(pull_force, pull_angle)
    end
  end
def do(actor, targets)
    #Acceleration will be limited by elapsed time.
    pull_force = delta
    targets.each do |target|
      #Angle from target to actor is also angle of pull force (opposite of that for push).
      pull_angle = Utility.find_angle(target.location, actor.location)
      #Apply the force to the creature's movement vector.
      target.vector += Vector.new(pull_force, pull_angle)
    end
  end
Pull the targets toward the actor, with force limited by elapsed time.