text: from django.utils.module_loading import autodiscover_modules
  
  OVERLAY_LAYERS = dict()
  
  
  def discover_layer_plugins():
      autodiscover_modules('overlay-layers')
  
  
  def get_overlay_layers():
      return OVERLAY_LAYERS
  
  
  def register_overlay_layer(name, cls):
      OVERLAY_LAYERS[name] = cls
  