code: def registerAddon(cls, name, addon, force=False):
          
          prop = '_{0}__addons'.format(cls.__name__)
          cmds = getattr(cls, prop, {})
  
          if name in cmds and not force:
              raise errors.AddonAlreadyExists(cls, name, addon)
  
          cmds[name] = addon
          try:
              if issubclass(addon, cls):
                  setattr(addon, '_{0}__addonName'.format(addon.__name__), name)
          except StandardError:
              pass
  
          setattr(cls, prop, cmds)
docs: Registers the inputted addon to the class.
          
          :param      name    | <str>
                      addon   | <variant>