16 and 17 are integer keys.
changeset code for outerstruct :
%MyOuterStruct{ key: :value,
inner_key:
%{16=> %InnerStruct{key2: :value2},
17=> %InnerStruct{key2: :value3}
}
we have typed structs and not using ecto schemas.
So, changesets for OuterStruct is written in a way that it invokes changeset for nested structs.
