code: def _register_allocator(self, plugin_name, plugin_instance):
          
          for allocator in plugin_instance.get_allocators().keys():
              if allocator in self._allocators:
                  raise PluginException("Allocator with name {} already exists! unable to add "
                                        "allocators from plugin {}".format(allocator, plugin_name))
              self._allocators[allocator] = plugin_instance.get_allocators().get(allocator)
docs: Register an allocator.
  
          :param plugin_name: Allocator name
          :param plugin_instance: RunPluginBase
          :return: