How to create a List in Scala from existing list with type conversion?
===

## Context
I've got a List like this : 

    List[(Long, String)]
   
and I need a List like this :

    List[(String, String)]
    
    
## Tried : 
   
My first "naive" attempt (coming from Java) was : 

    myList.map { t => t.myLongfield.toString, t.otherString }
    
And I've got a error :

	required List[(String, String)] 
	given List[(java.lang.String, String)]
