1
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You might not want duplicate values and to avoid that,

2
00:00:06,390 --> 00:00:15,680
you can use an alternative to push. Instead of push, you can use add to set, add to set does almost the same

3
00:00:15,960 --> 00:00:22,770
but if I run it, you see now we have no duplicate values because add to set essentially also pushes

4
00:00:23,070 --> 00:00:28,440
but avoids duplicate values. If it finds that an entry already exists,

5
00:00:28,500 --> 00:00:30,690
it just doesn't push the new value,

6
00:00:30,810 --> 00:00:32,780
this is what adds to set does.

7
00:00:32,940 --> 00:00:39,090
So with that, with unwind, with push in the group stage and with add to set in the group stage, you

8
00:00:39,080 --> 00:00:45,330
get powerful features that should help you manage your array data efficiently and transform it into

9
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whichever format you require.