diff --git a/vendor/go.etcd.io/etcd/raft/quorum/joint.go b/vendor/go.etcd.io/etcd/raft/quorum/joint.go
new file mode 100644
index 0000000..e3741e0
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/raft/quorum/joint.go
@@ -0,0 +1,75 @@
+// Copyright 2019 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 quorum
+
+// JointConfig is a configuration of two groups of (possibly overlapping)
+// majority configurations. Decisions require the support of both majorities.
+type JointConfig [2]MajorityConfig
+
+func (c JointConfig) String() string {
+	if len(c[1]) > 0 {
+		return c[0].String() + "&&" + c[1].String()
+	}
+	return c[0].String()
+}
+
+// IDs returns a newly initialized map representing the set of voters present
+// in the joint configuration.
+func (c JointConfig) IDs() map[uint64]struct{} {
+	m := map[uint64]struct{}{}
+	for _, cc := range c {
+		for id := range cc {
+			m[id] = struct{}{}
+		}
+	}
+	return m
+}
+
+// Describe returns a (multi-line) representation of the commit indexes for the
+// given lookuper.
+func (c JointConfig) Describe(l AckedIndexer) string {
+	return MajorityConfig(c.IDs()).Describe(l)
+}
+
+// CommittedIndex returns the largest committed index for the given joint
+// quorum. An index is jointly committed if it is committed in both constituent
+// majorities.
+func (c JointConfig) CommittedIndex(l AckedIndexer) Index {
+	idx0 := c[0].CommittedIndex(l)
+	idx1 := c[1].CommittedIndex(l)
+	if idx0 < idx1 {
+		return idx0
+	}
+	return idx1
+}
+
+// VoteResult takes a mapping of voters to yes/no (true/false) votes and returns
+// a result indicating whether the vote is pending, lost, or won. A joint quorum
+// requires both majority quorums to vote in favor.
+func (c JointConfig) VoteResult(votes map[uint64]bool) VoteResult {
+	r1 := c[0].VoteResult(votes)
+	r2 := c[1].VoteResult(votes)
+
+	if r1 == r2 {
+		// If they agree, return the agreed state.
+		return r1
+	}
+	if r1 == VoteLost || r2 == VoteLost {
+		// If either config has lost, loss is the only possible outcome.
+		return VoteLost
+	}
+	// One side won, the other one is pending, so the whole outcome is.
+	return VotePending
+}