public T visitListTypeSpecifier(ListTypeSpecifier elm, C context) {
        visitElement(elm.getElementType(), context);
        return null;
    }
public T visitListTypeSpecifier ( ListTypeSpecifier elm , C context ) { visitElement ( elm . getElementType ( ) , context ) ; return null ; }
Visit a ListTypeSpecifier. This method will be called for
every node in the tree that is a ListTypeSpecifier.

@param elm     the ELM tree
@param context the context passed to the visitor
@return the visitor result