| context | Package context defines the Context type, which carries deadlines, cancellation signals, and other request-scoped values across API boundaries and between processes. |
| errors | Package errors implements functions to manipulate errors. |
| golang.org/x/net/dns/dnsmessage | Package dnsmessage provides a mostly RFC 1035 compliant implementation of DNS message packing and unpacking. |
| internal/bytealg | |
| internal/nettrace | Package nettrace contains internal hooks for tracing activity in the net package. |
| internal/poll | Package poll supports non-blocking I/O on file descriptors with polling. |
| internal/singleflight | Package singleflight provides a duplicate function call suppression mechanism. |
| io | Package io provides basic interfaces to I/O primitives. |
| math/rand | Package rand implements pseudo-random number generators suitable for tasks such as simulation, but it should not be used for security-sensitive work. |
| os | Package os provides a platform-independent interface to operating system functionality. |
| runtime | Package runtime contains operations that interact with Go's runtime system, such as functions to control goroutines. |
| sort | Package sort provides primitives for sorting slices and user-defined collections. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |
| syscall | Package syscall contains an interface to the low-level operating system primitives. |
| time | Package time provides functionality for measuring and displaying time. |