docs: def registry_storage(cls):
  		""" Get registry storage
  
  		:return: WTaskRegistryBase
  		"""
  		if cls.__registry_storage__ is None:
  			raise ValueError('__registry_storage__ must be defined')
  		if isinstance(cls.__registry_storage__, WTaskRegistryBase) is False:
  			raise TypeError("Property '__registry_storage__' is invalid (must derived from WTaskRegistryBase)")
  
  		return cls.__registry_storage__