Builder pattern standard

gistfile1.scala

case class AuthorBuilder(familyName: String = "John",
                         givenNames: Seq[String] = Seq("Doe"),
                         books: Seq[String] = Seq(),
                         affiliations: Seq[String] = Seq()) {
  def asXML =
    <Author>
      <FamilyName>{familyName}</FamilyName>
      <GivenNames>
        {for (name <- givenNames) yield <GivenName>{name}</GivenName>}
      </GivenNames>
      <Books>
        {for (id <- books) yield <Book>{id}</Book>}
      </Books>
      <Affiliations>
        {for (id <- affiliations) yield <Organisation>{id}</Organisation>}
      </Affiliations>
    </Author>
}