Constructors.cs

public class User
{
  public string Email {get; set;}
  public string FirstName {get; set;}
  public string LastName {get; set;}
  public string Password {get; set;}
  
  public void User()
  {    
  }
  
  public void User(string email)
  {
    Email = email;
  }
  
  public void User(string email, string firstName, string lastName)
    :this(email)
  {
    FirstName = firstName;
    LastName = lastName;
  }
  
  public void User(string email, string firstName, string lastName, string password)
    : this(email, firstName, lastName)
  {
    Password = password;
  }
}