| archive/zip | Package zip provides support for reading and writing ZIP archives. | 
    | fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. | 
    | golang.org/x/tools/godoc/vfs | Package vfs defines types for abstract file system access and provides an implementation accessing the file system of the underlying OS. | 
    | io | Package io provides basic interfaces to I/O primitives. | 
    | os | Package os provides a platform-independent interface to operating system functionality. | 
    | path | Package path implements utility routines for manipulating slash-separated paths. | 
    | sort | Package sort provides primitives for sorting slices and user-defined collections. | 
    | strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. | 
    | time | Package time provides functionality for measuring and displaying time. |