VOL-1921 - updated to use go mod

Change-Id: I8d5187fa91fa619494f972bc29d3bd61e5be3a82
diff --git a/vendor/go.etcd.io/etcd/pkg/types/set.go b/vendor/go.etcd.io/etcd/pkg/types/set.go
index c111b0c..e7a3cdc 100644
--- a/vendor/go.etcd.io/etcd/pkg/types/set.go
+++ b/vendor/go.etcd.io/etcd/pkg/types/set.go
@@ -148,6 +148,14 @@
 func (ts *tsafeSet) Equals(other Set) bool {
 	ts.m.RLock()
 	defer ts.m.RUnlock()
+
+	// If ts and other represent the same variable, avoid calling
+	// ts.us.Equals(other), to avoid double RLock bug
+	if _other, ok := other.(*tsafeSet); ok {
+		if _other == ts {
+			return true
+		}
+	}
 	return ts.us.Equals(other)
 }
 
@@ -173,6 +181,15 @@
 func (ts *tsafeSet) Sub(other Set) Set {
 	ts.m.RLock()
 	defer ts.m.RUnlock()
+
+	// If ts and other represent the same variable, avoid calling
+	// ts.us.Sub(other), to avoid double RLock bug
+	if _other, ok := other.(*tsafeSet); ok {
+		if _other == ts {
+			usResult := NewUnsafeSet()
+			return &tsafeSet{usResult, sync.RWMutex{}}
+		}
+	}
 	usResult := ts.us.Sub(other).(*unsafeSet)
 	return &tsafeSet{usResult, sync.RWMutex{}}
 }