Typescript type RouteConfig TypeError

[GUEThe]

What problem does this feature solve?

none

What does the proposed API look like?

When traverse RouteConfig[], read property 'children' of item. Get this error:
Property 'children' does not exist on type 'RouteConfig'.
Property 'children' does not exist on type 'RouteConfigSingleView'
Type 'RouteConfigMultipleViews' has property 'children', but 'RouteConfigSingleView' doesn't.
Type 'RouteConfigMultipleViews' and type 'RouteConfigSingleView' wasn't exported.