| crypto/rand | Package rand implements a cryptographically secure random number generator. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| github.com/hashicorp/golang-lru/simplelru | Package simplelru provides simple LRU implementation based on build-in container/list. |
| math | Package math provides basic constants and mathematical functions. |
| math/big | Package big implements arbitrary-precision arithmetic (big numbers). |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |
| testing | Package testing provides support for automated testing of Go packages. |