in `riak_kv_vnode.hrl` , we have other requests such as 
```
-define(KV_PUT_REQ, #riak_kv_put_req_v1).
-define(KV_GET_REQ, #riak_kv_get_req_v1).
-define(KV_LISTBUCKETS_REQ, #riak_kv_listbuckets_req_v1).
-define(KV_LISTKEYS_REQ, #riak_kv_listkeys_req_v4).
-define(KV_INDEX_REQ, #riak_kv_index_req_v2).
-define(KV_VNODE_STATUS_REQ, #riak_kv_vnode_status_req_v1).
-define(KV_DELETE_REQ, #riak_kv_delete_req_v1).
-define(KV_MAP_REQ, #riak_kv_map_req_v1).
-define(KV_VCLOCK_REQ, #riak_kv_vclock_req_v1).
```
So I think we should handle all of these requests here. Or other code to handle these requests in somewhere else?