The codes are pasted below:

```
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)
}

```

I know the first parentheses `(tag: Tag)` means the parameter list of `Suppliers`, and the second part `Table[(String, String, Int, String)]` means a `super class with generic`. 

But what does `(tag, "suppliers")` mean? Is it a decorator to the superclass `Table` or the defined class `Supplier`. Is there any document about this?