It was because of the signature of keys-and-attrs which has now been changed to an agnostic argument form. So basically batch-get-item can be called in one of two ways:
```clojure
(batch-get-item cred table [1 2 3 4]) 
```
which seems a nice convenience for the caller if they just have a collection of keys they want to fetch, or
```clojure
(batch-get-item cred {
  table {
  :consistent true
  :attrs [\"id\" \"username\"]
  :keys [1 2 3 4]}})
```
if they want to fetch from more than one table in one request, or force read consistency or declare a projection of attrs.