code: def set_nested_attribute(obj, attribute, value):
      
      parent, attr = resolve_nested_attribute(obj, attribute)
      if parent is None:
          raise AttributeError('Can not set attribute "%s" on None value.'
                               % attr)
      setattr(parent, attr, value)
docs: Sets the value of the given (possibly dotted) attribute for the given
      object to the given value.
  
      :raises AttributeError: If any of the parents on the nested attribute's
        name path are `None`.