Reports & Discoverer :: Building Reports In Dev - 10g With Ref Cursor Query?

i was searching for the example of subject mentioned and visited the following website

[URL]...

here is a tutorial to create such report, but i am confused as here in Report's Data Model they created 3 Ref Cursor Queries and did not Close the opened cursor, is there no need of this or any mistake or if it necessary, where have to Close the cursor?First, they have created following Packages

PACKAGE concl_cv IS
type conclass_rec is RECORD
(EMPLOYEE_ID NUMBER(6),
FIRST_NAME VARCHAR2(20),
LAST_NAME VARCHAR2(25),

[code]...

then, created Functions which created in Ref Cursor Query in Data Model
function q_portdescRefCurDS return port_cv.portdesc_refcur is
temp_portdesc port_cv.portdesc_refcur;
begin
open temp_portdesc for select department_id, department_name from departments;

[code]...

nothing here any Close cursor statement.i am trying to explore this area of the development.