php: add call getTrailingMetadata API
diff --git a/src/php/lib/Grpc/UnaryCall.php b/src/php/lib/Grpc/UnaryCall.php
index b57903d..b114b77 100644
--- a/src/php/lib/Grpc/UnaryCall.php
+++ b/src/php/lib/Grpc/UnaryCall.php
@@ -75,6 +75,8 @@
             OP_RECV_STATUS_ON_CLIENT => true,
         ]);
 
-        return [$this->deserializeResponse($event->message), $event->status];
+        $status = $event->status;
+        $this->trailing_metadata = $status->metadata;
+        return [$this->deserializeResponse($event->message), $status];
     }
 }