export interface FI { street: string zipCode: string city: string countryCode: "FI" } export namespace FI { export function is(value: any | FI): value is FI { return ( typeof value == "object" && typeof value.street == "string" && typeof value.zipCode == "string" && typeof value.city == "string" && value.countryCode == "FI" ) } export function create(): FI { return { street: "", zipCode: "", city: "", countryCode: "FI" } } }