//go get github.com/emirpasic/gods/sets/hashset
import (
"fmt"
"github.com/emirpasic/gods/sets/hashset"
)
chars := hashset.New('A', 'B', 'C', 'D')
var containA = chars.Contains('A')
//containA is true
var containE = chars.Contains('E')
//containE is False
var containAll = chars.Contains('A', 'B')
//containAll is true
fmt.Println("containA is", containA)
fmt.Println("containE is", containE)
fmt.Println("containAll is", containAll)