Reducing duplication of static methods in schemas

export class PendingEnrollment extends Schema.Class<PendingEnrollment>('PendingEnrollment')({
  status: Schema.Literal('Pending'),
  id: EnrollmentId,
  createdAt: Schema.Date,
}) {
  static asserts: Schema.Schema.ToAsserts<typeof this> = Schema.asserts(this);
}

export class ActiveEnrollment extends Schema.Class<ActiveEnrollment>('ActiveEnrollment')({
  status: Schema.Literal('Active'),
  id: EnrollmentId,
  createdAt: Schema.Date,
  activatedAt: Schema.Date,
}) {
  static asserts: Schema.Schema.ToAsserts<typeof this> = Schema.asserts(this);
}

export class InactiveEnrollment extends Schema.Class<ActiveEnrollment>('InactiveEnrollment')({
  status: Schema.Literal('Inactive'),
  id: EnrollmentId,
  createdAt: Schema.Date,
  activatedAt: Schema.Date,
  deactivatedAt: Schema.Date,
}) {
  static asserts: Schema.Schema.ToAsserts<typeof this> = Schema.asserts(this);
}

static asserts: Schema.Schema.ToAsserts<typeof this> = Schema.asserts(this);

export class State extends Schema.Class<State>('State')({}) {
  static asserts: Schema.Schema.ToAsserts<typeof this> = Schema.asserts(this);
}

export class PendingEnrollment extends State.extend<PendingEnrollment>('PendingEnrollment')({
  status: Schema.Literal('Pending'),
  id: EnrollmentId,
  createdAt: Schema.Date,
}) {}

PendingEnrollment.asserts; // TS2339: Property asserts; does not exist on type typeof PendingEnrollment