type String map[string]interface{}
func (s String) Difference(s2 String) String
func (s String) Has(val string) bool
func (s String) Insert(vals ...string)
func (s String) Intersection(s2 String) String
func (s String) Len() int
func (s String) List() []string
func (s String) SymmetricDifference(s2 String) String
StringList is a set, where each element of the set is a string slice.
type StringList [][]string
func (s StringList) Has(val []string) bool
func (s StringList) Insert(val []string) StringList
func (s StringList) Len() int