How to fill in maps in go?

Question

go

There is such a type:
map[int]map[int]map[int]int
To store such a data structure:

-- [ id ]
------ [ group_id ]
---------- [ item_id ]
-------------- [ quantity ]
---------- [ item_id ]
-------------- [ quantity ]
---------- [ item_id ]
-------------- [ quantity ]
------ [ group_id ]
---------- [ item_id ]
-------------- [ quantity ]
--[ id ]
------ [ group_id ]
---------- [ item_id ]
-------------- [ quantity ]

How to correctly add group_id to such maps?
Right now I'm doing something like this:

if _, ok := my_map[group_id]; !ok {
    my_map[group_id] = make(map[int]int)
}
my_map[group_id][item_id] = quantity

and then my_map is added to the global map, this code seems too scary to me, maybe there are best practices for working with such data?
Is it possible to implement this only with slices?

Answer 1

Go has OOP, use it. Highlight your Item, Group, etc. at least like this

Answer 2

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Subject: Permission!