Retrieve group from symbian using J2ME

I got the Contact List of symbian but not getting the group. for getting the contactlist i have coded

PIM pim;

pim=PIM.getInstance();

ContactList clist=null;

clist=(ContactList)pim.openPIMList(PIM.CONTACT_LIST, PIM.READ_WRITE);

Contact c=null;

Enumeration contacts=clist.items();

while(contacts.hasMoreElements()){
                c=(Contact)contacts.nextElement();
...
...
}

now how to get the group and retrieve group members ?

Typically, groups should be implemented using JSR-75 Categories.

Try using:

PIMList.getCategories()
PIMList.itemsByCategory()
PIMItem.getCategories()