func (f StringOption) ApplyPositional(set *flags.Set) {
if f.EnvVar != "" {
if envVal := os.Getenv(f.EnvVar); envVal != "" {
f.Value = envVal
}
}
eachName(f.Name, func(name string) {
set.StringArg(name, f.Value, f.Usage, f.Var, f.Optional)
})
}
