public void GetIdentifierHashCode_ReturnsHashCodeOfPatientID()
        {
            // Arrange
            var birthNumber = new BirthNumber("9107256444");
            var patient = new PatientInfo
            {
                PatientID = birthNumber
            };

            // Act
            int hashCode = patient.GetIdentifierHashCode();

            // Assert
            Assert.That(hashCode, Is.EqualTo(birthNumber.GetHashCode()));
        }