old_contents: import abc
  
  from displayable import Displayable
  
  class Turnable(Displayable):
      """Base class for any object that can change it's rotation on gaming
      field.
  
      Fields:
  
      angle is turn angle for this object.
  
      angular_speed is speed of rotation of object at this moment.
  
      max_angular_speed is maximum of absolute value of turning speed. Clockwise
      rotation speed equals to counterclockwise rotation speed."""
  
      def __init__(self, init_angle, init_angular_speed, max_angular_speed):
          self._angle = init_angle
          self._angular_speed = init_angular_speed
          self._max_angular_speed = max_angular_speed
  
      def turn_on_angle(self):
          """Turns this object on given angle, if direction "forward" can be
          defined."""
          self._angle += self._angular_speed
  
      def set_angular_speed(self, angular_speed):
          """Sets angular speed with check."""
          if angular_speed > self._max_angular_speed:
              self._angular_speed = self._max_angular_speed
          elif angular_speed < -self._max_angular_speed:
              self._angular_speed = -self._max_angular_speed
          else:
              self._angular_speed = angular_speed
  
      #   TODO: implement when we define strictly how angle is measured
      def turn_to_face(self, x, y):
          """Turns this object to be positioned to point (x,y)"""
          raise NotImplementedError("Not implemented yet")
  
new_contents: from displayable import Displayable
  
  class Turnable(Displayable):
      """
      Base class for any object that can change it's 
      rotation on gaming field.
      
      angle - turn angle for this object.
      angular_speed - speed of rotation of object at this moment.
      max_angular_speed - maximum of absolute value of turning speed. Clockwise
      rotation speed - equals to counterclockwise rotation speed.
      
      turn_on_angle(self)
      set_angular_speed(self, angular_speed)
      turn_to_face(self, x, y)
      """
  
      def __init__(self, init_angle, init_angular_speed, max_angular_speed):
          self._angle = init_angle
          self._angular_speed = init_angular_speed
          self._max_angular_speed = max_angular_speed
  
      def turn_on_angle(self):
          """Turns this object on given angle, if direction "forward" can be
          defined."""
          self._angle += self._angular_speed
  
      def set_angular_speed(self, angular_speed):
          """Sets angular speed with check."""
          if angular_speed > self._max_angular_speed:
              self._angular_speed = self._max_angular_speed
          elif angular_speed < -self._max_angular_speed:
              self._angular_speed = -self._max_angular_speed
          else:
              self._angular_speed = angular_speed
  
      #   TODO: implement when we define strictly how angle is measured
      def turn_to_face(self, x, y):
          """Turns this object to be positioned to point (x,y)"""
          raise NotImplementedError("Not implemented yet")
  
subject: Update turnable.py