old_contents: 
  
  class Renderer(object):
      __created = False
      def __init__(self):
          if self.__class__.__created:
              raise Exception("Renderer already exists!")
          self.__objects = []
          self.__class__.__created = True
  
      def __del__(self):
          self.__class__.__created = False
  
      def add_object(self, obj):
          self.__objects.append(obj)
  
      def remove_object(self, obj):
          self.__objects.remove(obj)
  
      def render_all(self, screen):
          for obj in self.__objects:
              for image, pos in obj.get_render_data():
                  screen.addch(pos.y, pos.x, image, obj.style)
  
new_contents: class Renderer(object):
      def __init__(self):
          self.__objects = []
  
  
      def add_object(self, obj):
          self.__objects.append(obj)
  
  
      def remove_object(self, obj):
          self.__objects.remove(obj)
  
  
      def render_all(self, screen):
          for obj in self.__objects:
              glob_pos, data_gen = obj.get_render_data()
              for el in data_gen:
                  pos, image, style = el
                  screen.addch(glob_pos.y + pos.y, glob_pos.x + pos.x, image)
  
subject: remove singleton's check, I don't need this... Fix render_all.