Java vs Ruby vs Scala

JavaAccount.java

public class Account implements Serializable {
  private String subdomain;
  
  public String getSubdomain() {
    return subdomain;
  }
  
  public void setSubdomain(String subdomain) {
    this.subdomain = subdomain;
  }
}

RubyAccount.rb

class Account {
  include Serializable
  
  attr_accessor :subdomain
}

ScalaAccount.scala

class Account(var subdomain : String) with Serializable