export type CarLicenseType = 'R' | 'D' | 'C' | 'B' | 'A' | 'Pro'; export class CarLicense { private constructor(private readonly value: CarLicenseType) {} static create(value: CarLicenseType): CarLicense { return new CarLicense(value); } toString(): CarLicenseType { return this.value; } equals(other: CarLicense): boolean { return this.value === other.value; } }