[VOL-1550] Support for OLT hard reboot with ONU connected

Change-Id: I67642d847d2308f8abf8e9b90986eeecf65b2a41
diff --git a/vendor/github.com/opencord/voltha-go/db/model/proxy.go b/vendor/github.com/opencord/voltha-go/db/model/proxy.go
index 2933464..d4a86f4 100644
--- a/vendor/github.com/opencord/voltha-go/db/model/proxy.go
+++ b/vendor/github.com/opencord/voltha-go/db/model/proxy.go
@@ -150,6 +150,19 @@
 	PROXY_CREATE
 )
 
+var proxyOperationTypes = []string{
+	"PROXY_GET",
+	"PROXY_LIST",
+	"PROXY_ADD",
+	"PROXY_UPDATE",
+	"PROXY_REMOVE",
+	"PROXY_CREATE",
+}
+
+func (t ProxyOperation) String() string {
+	return proxyOperationTypes[t]
+}
+
 // parseForControlledPath verifies if a proxy path matches a pattern
 // for locations that need to be access controlled.
 func (p *Proxy) parseForControlledPath(path string) (pathLock string, controlled bool) {