code: func (fs *FlagSet) Int(names []string, value int, usage string) *int {
  	p := new(int)
  	fs.IntVar(p, names, value, usage)
  	return p
  }
docs: // 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.