code: def bind(self, container):
          
  
          def clone(prototype):
              if prototype.is_bound():
                  raise RuntimeError('Cannot `bind` a bound extension.')
  
              cls = type(prototype)
              args, kwargs = prototype.__params
              instance = cls(*args, **kwargs)
              # instance.container must be a weakref to avoid a strong reference
              # from value to key in the `shared_extensions` weakkey dict
              # see test_extension_sharing.py: test_weakref
              instance.container = weakref.proxy(container)
              return instance
  
          instance = clone(self)
  
          # recurse over sub-extensions
          for name, ext in inspect.getmembers(self, is_extension):
              setattr(instance, name, ext.bind(container))
          return instance
docs: Get an instance of this Extension to bind to `container`.