pkg flag, func Lookup(string) *Flag
pkg flag, func NArg() int
pkg flag, func NFlag() int
pkg flag, func NewFlagSet(string, ErrorHandling) *FlagSet
pkg flag, func Parse()
pkg flag, func Parsed() bool
pkg flag, func PrintDefaults()
pkg flag, func Set(string, string) error
pkg flag, func String(string, string, string) *string
pkg flag, func StringVar(*string, string, string, string)

  If you modify a copy of the Library, and, in your modifications, a
facility refers to a function or data to be supplied by an Application
that uses the facility (other than as an argument passed when the
facility is invoked), then you may convey a copy of the modified
version:

   a) under this License, provided that you make a good faith effort to