the header is :

(ListInterfaceT>doubleIt(ListInterfaceT>list){

QUESTION 3 [10 points] and returns a new ListInterface T where every element from 1 ist is doubled. For example if 1 ist contained the elements {X,Y,Z} then doubleIt( ) will return a new list with the values {X,X,Y,Y,Z,Z} The method header is provided