Interface RailLine<S>

interface RailLine<S extends boolean = true> {
    code: string;
    colour: null | Sourced<string, S>;
    company: Sourced<number, S>;
    i: number;
    mode: null | Sourced<RailMode, S>;
    name: null | Sourced<string, S>;
    ref_station: Sourced<number, S>;
    source: string[];
    type: string;
}