3. Suppose you have a linked list structure and a node structure de defined as follows template class 11ist ( tonplats prevheaderi header->next -header node (const T& x, nodecT.y-NULL. nodesT*z-NULL) val (x) next(y), prev(z) o void unique ; 2: Write the 1list member functi ion unique, which removes all consecutive duplicate elements from the list. If any two elenents in a row are the same, remove one of therm