anchor.diff:          %% LUMA API Key, must be identical with API Key in external LUMA
           %% service.
           lumaApiKey => {string, optional},
  -        %% The type of storage.
  -        type => {equal, <<"webdav">>},
           %% Full URL of the WebDAV server, including scheme (http or https) and
           %% path.
           endpoint => string,
  
positive.code:         %% LUMA API Key, must be identical with API Key in external LUMA
          %% service.
          lumaApiKey => {string, optional},
          %% The type of storage.
          type => {equal, <<"swift">>},
          %% The URL to OpenStack Keystone identity service.
          authUrl => string,
          %% The name of the tenant to which the user belongs.
  
negative.code: -spec webdav_model() -> maps:map().
  webdav_model() ->
      #{
          %% The type of storage.
          type => {equal, <<"webdav">>},
          %% The Id of storage.
          id => {string, optional},
          %% The name of storage.
  