envflag.go
func Int(name string, value int, usage string) *int {
	return EnvironmentFlags.Int(name, value, usage)
}
func Int(name string, value int, usage string) *int {
	return EnvironmentFlags.Int(name, value, usage)
}
// Int defines an int flag with specified name, default value, and
// usage string.  The return value is the address of an int variable
// that stores the value of the flag.