title: Slick 2.0.0-M3 table definition - clarification on the tag attribute
body: <p>I'm working on migrating to slick 2 but I've come across a class that I can't seem to find anywhere. </p>
  
  <pre><code>package learningSlick
  
  import scala.slick.driver.MySQLDriver.simple._
  
  case class Supplier( snum: String, sname: String, status: Int, city: String )
  
  class Suppliers(tag: Option[String]) extends Table[Supplier](tag, "suppliers") {
    def snum  = column[String]("snum")
    def sname = column[String]("sname")
    def status   = column[Int]("status")
    def city     = column[String]("city")
    def * = snum ~ sname ~ status ~ city &lt;&gt; (Supplier, Supplier.unapply _)
  }
  </code></pre>
  
  <p>The following is the code from the tutorial:</p>
  
  <pre><code>import scala.slick.driver.PostgresDriver.simple._
  
  class Suppliers(tag: Tag) extends Table[(String, String, Int, String)](tag, "suppliers") {
      def    snum = column[String]("snum")
      def sname = column[String]("sname")
      def status = column[Int]("status")
      def city = column[String]("city")
      def * = (snum, sname, status, city) 
  }
  </code></pre>
  
  <p>In the definition for Table it says that the Tag is of type Option[String] however in a tutorial I'm going through it just uses a type of Tag.  I'm looking for which package this is coming from. </p>