diff --git a/vendor/go.etcd.io/etcd/lease/lease_queue.go b/vendor/go.etcd.io/etcd/lease/lease_queue.go
new file mode 100644
index 0000000..17ddb35
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/lease/lease_queue.go
@@ -0,0 +1,106 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package lease
+
+import "container/heap"
+
+// LeaseWithTime contains lease object with a time.
+// For the lessor's lease heap, time identifies the lease expiration time.
+// For the lessor's lease checkpoint heap, the time identifies the next lease checkpoint time.
+type LeaseWithTime struct {
+	id LeaseID
+	// Unix nanos timestamp.
+	time  int64
+	index int
+}
+
+type LeaseQueue []*LeaseWithTime
+
+func (pq LeaseQueue) Len() int { return len(pq) }
+
+func (pq LeaseQueue) Less(i, j int) bool {
+	return pq[i].time < pq[j].time
+}
+
+func (pq LeaseQueue) Swap(i, j int) {
+	pq[i], pq[j] = pq[j], pq[i]
+	pq[i].index = i
+	pq[j].index = j
+}
+
+func (pq *LeaseQueue) Push(x interface{}) {
+	n := len(*pq)
+	item := x.(*LeaseWithTime)
+	item.index = n
+	*pq = append(*pq, item)
+}
+
+func (pq *LeaseQueue) Pop() interface{} {
+	old := *pq
+	n := len(old)
+	item := old[n-1]
+	item.index = -1 // for safety
+	*pq = old[0 : n-1]
+	return item
+}
+
+// LeaseExpiredNotifier is a queue used to notify lessor to revoke expired lease.
+// Only save one item for a lease, `Register` will update time of the corresponding lease.
+type LeaseExpiredNotifier struct {
+	m     map[LeaseID]*LeaseWithTime
+	queue LeaseQueue
+}
+
+func newLeaseExpiredNotifier() *LeaseExpiredNotifier {
+	return &LeaseExpiredNotifier{
+		m:     make(map[LeaseID]*LeaseWithTime),
+		queue: make(LeaseQueue, 0),
+	}
+}
+
+func (mq *LeaseExpiredNotifier) Init() {
+	heap.Init(&mq.queue)
+	mq.m = make(map[LeaseID]*LeaseWithTime)
+	for _, item := range mq.queue {
+		mq.m[item.id] = item
+	}
+}
+
+func (mq *LeaseExpiredNotifier) RegisterOrUpdate(item *LeaseWithTime) {
+	if old, ok := mq.m[item.id]; ok {
+		old.time = item.time
+		heap.Fix(&mq.queue, old.index)
+	} else {
+		heap.Push(&mq.queue, item)
+		mq.m[item.id] = item
+	}
+}
+
+func (mq *LeaseExpiredNotifier) Unregister() *LeaseWithTime {
+	item := heap.Pop(&mq.queue).(*LeaseWithTime)
+	delete(mq.m, item.id)
+	return item
+}
+
+func (mq *LeaseExpiredNotifier) Poll() *LeaseWithTime {
+	if mq.Len() == 0 {
+		return nil
+	}
+	return mq.queue[0]
+}
+
+func (mq *LeaseExpiredNotifier) Len() int {
+	return len(mq.m)
+}