Added arn to the main repository

arn/HasLocked.go

@@ -0,0 +1,21 @@
+package arn
+
+// HasLocked implements common like and unlike methods.
+type hasLocked struct {
+	Locked bool `json:"locked"`
+}
+
+// Lock locks the object.
+func (obj *hasLocked) Lock(userID UserID) {
+	obj.Locked = true
+}
+
+// Unlock unlocks the object.
+func (obj *hasLocked) Unlock(userID UserID) {
+	obj.Locked = false
+}
+
+// IsLocked implements the Lockable interface.
+func (obj *hasLocked) IsLocked() bool {
+	return obj.Locked
+}