# Faster function for working with cosets

I would like to get the cosets of a non-normal subgroup and in the documentation for the `.cosets()`

method here:

PermutationGroup_generic.cosets

there is a **Note:** that says

Sage and GAP provide more sophisticated functions for working quickly with cosets of larger groups.

but doesn't mention what these functions are. I was hoping that someone could point me to these functions.

If it makes a difference, I want to iterate over a set of coset representatives and it will all be done in a permutation group.