// The idea is to try to change the values from the outside of the method
        private static void Main(string[] args)
        {
            // Value type
            var personVal = new PersonValue
            {
                Name = "Diana",
                Age  = 35
            };

            Console.WriteLine("personVal: {0}", personVal.ToString());
            ChangePersonValue(personVal);
            Console.WriteLine("personVal: {0}", personVal.ToString());

            // Reference type
            var personRef = new PersonReference
            {
                Name = "John",
                Age  = 40
            };

            Console.WriteLine("personRef: {0}", personRef.ToString());
            ChangePersonReference(personRef);
            Console.WriteLine("personRef: {0}", personRef.ToString());
        }
 // Tries to change the value of the properties
 // It changes the value but doesn't return anything
 // Nothing happens, no new values
 private static void ChangePersonValue(PersonValue personValue)
 {
     personValue.Name = "Martha";
     personValue.Age  = 50;
 }