| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| github.com/mailru/easyjson | Package easyjson contains marshaler/unmarshaler interfaces and helper functions. |
| github.com/mailru/easyjson/jlexer | Package jlexer contains a JSON lexer implementation. |
| github.com/mailru/easyjson/jwriter | Package jwriter contains a JSON writer. |
| github.com/mailru/easyjson/opt | |
| math | Package math provides basic constants and mathematical functions. |
| net | Package net provides a portable interface for network I/O, including TCP/IP, UDP, domain name resolution, and Unix domain sockets. |
| time | Package time provides functionality for measuring and displaying time. |