| errors | Package errors implements functions to manipulate errors. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| github.com/coreos/etcd/clientv3 | clientv3 is the official Go etcd client for v3. |
| github.com/coreos/etcd/mvcc/mvccpb | |
| golang.org/x/net/context | Package context defines the Context type, which carries deadlines, cancellation signals, and other request-scoped values across API boundaries and between processes. |
| math | Package math provides basic constants and mathematical functions. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |