func NewItem(id string) Item {
	return Item{
		I: id,
		S: true,
	}
}
NewItem creates a Item with success status.
package teststate
import (
	"encoding/json"
	"fmt"
	"sort"
	"github.com/golang-collections/go-datastructures/queue"
	"github.com/pkg/errors"
	"github.com/google/simhospital/pkg/state/persist"
)
const (
	Type = "test-type"
)
var (
	Item1 = NewItem("1")
	Item2 = NewItem("2")
)
type Item struct {
	I string
	S bool
}
func (i Item) ID() (string, error) {
	return i.I, nil
}
func (i Item) Marshal() ([]byte, error) {
	if i.S {
		return json.Marshal(i)
	}
	return nil, errors.New("unsuccessful marshal")
}
func (i Item) Compare(other queue.Item) int {
	o, ok := other.(Item)
	if !ok {
		panic(fmt.Sprintf("Incompatible type: trying to compare Item with %v", other))
	}
	if i.I > o.I {
		return 1
	}
	return -1
}