| bytes | Package bytes implements functions for the manipulation of byte slices. |
| flag | Package flag implements command-line flag parsing. |
| golang.org/x/tools/go/packages | Package packages loads Go packages for inspection and analysis. |
| io/ioutil | Package ioutil implements some I/O utility functions. |
| log | Package log implements a simple logging package. |
| path/filepath | Package filepath implements utility routines for manipulating filename paths in a way compatible with the target operating system-defined file paths. |
| text/template | Package template implements data-driven templates for generating textual output. |