func (s Int) Delete(items ...int) {
	for _, item := range items {
		delete(s, item)
	}
}
Delete removes all items from the set.
package sets
import (
	"reflect"
	"sort"
)
type Int map[int]Empty
func NewInt(items ...int) Int {
	ss := Int{}
	ss.Insert(items...)
	return ss
}
func IntKeySet(theMap interface{}) Int {
	v := reflect.ValueOf(theMap)
	ret := Int{}
	for _, keyValue := range v.MapKeys() {
		ret.Insert(keyValue.Interface().(int))
	}
	return ret
}
func (s Int) Insert(items ...int) {
	for _, item := range items {
		s[item] = Empty{}
	}
}