TAG: ObjectSchema<
    {
        end: OptionalSchema<NumberSchema<undefined>, undefined>;
        start: OptionalSchema<NumberSchema<undefined>, undefined>;
        type: PicklistSchema<
            ("ExpressionTag" | "ConstTag" | "DebugTag" | "HtmlTag" | "RenderTag")[],
            undefined,
        >;
    },
    undefined,
> = ...

Schema of AST.Tag for validation purposes. @NO_SIDE_EFFECTS