re-generate PHP files
diff --git a/src/php/tests/generated_code/Math/MathClient.php b/src/php/tests/generated_code/Math/MathClient.php
index f8b626b..2a2852b 100644
--- a/src/php/tests/generated_code/Math/MathClient.php
+++ b/src/php/tests/generated_code/Math/MathClient.php
@@ -37,7 +37,7 @@
      * @param \Math\DivArgs $argument input argument
      * @param array $metadata metadata
      * @param array $options call options
-     * @return \Math\DivReply
+     * @return \Grpc\UnaryCall
      */
     public function Div(\Math\DivArgs $argument,
       $metadata = [], $options = []) {
@@ -54,7 +54,7 @@
      * replies.  The stream ends immediately if either end aborts.
      * @param array $metadata metadata
      * @param array $options call options
-     * @return \Math\DivReply
+     * @return \Grpc\BidiStreamingCall
      */
     public function DivMany($metadata = [], $options = []) {
         return $this->_bidiRequest('/math.Math/DivMany',
@@ -69,7 +69,7 @@
      * @param \Math\FibArgs $argument input argument
      * @param array $metadata metadata
      * @param array $options call options
-     * @return \Math\Num
+     * @return \Grpc\ServerStreamingCall
      */
     public function Fib(\Math\FibArgs $argument,
       $metadata = [], $options = []) {
@@ -84,7 +84,7 @@
      * is closed.
      * @param array $metadata metadata
      * @param array $options call options
-     * @return \Math\Num
+     * @return \Grpc\ClientStreamingCall
      */
     public function Sum($metadata = [], $options = []) {
         return $this->_clientStreamRequest('/math.Math/Sum',
diff --git a/src/php/tests/interop/Grpc/Testing/LoadBalancerStatsServiceClient.php b/src/php/tests/interop/Grpc/Testing/LoadBalancerStatsServiceClient.php
index cfbd0fd..3b23ff6 100644
--- a/src/php/tests/interop/Grpc/Testing/LoadBalancerStatsServiceClient.php
+++ b/src/php/tests/interop/Grpc/Testing/LoadBalancerStatsServiceClient.php
@@ -40,7 +40,7 @@
      * @param \Grpc\Testing\LoadBalancerStatsRequest $argument input argument
      * @param array $metadata metadata
      * @param array $options call options
-     * @return \Grpc\Testing\LoadBalancerStatsResponse
+     * @return \Grpc\UnaryCall
      */
     public function GetClientStats(\Grpc\Testing\LoadBalancerStatsRequest $argument,
       $metadata = [], $options = []) {
diff --git a/src/php/tests/interop/Grpc/Testing/ReconnectServiceClient.php b/src/php/tests/interop/Grpc/Testing/ReconnectServiceClient.php
index 695d83a..bed9446 100644
--- a/src/php/tests/interop/Grpc/Testing/ReconnectServiceClient.php
+++ b/src/php/tests/interop/Grpc/Testing/ReconnectServiceClient.php
@@ -39,7 +39,7 @@
      * @param \Grpc\Testing\ReconnectParams $argument input argument
      * @param array $metadata metadata
      * @param array $options call options
-     * @return \Grpc\Testing\EmptyMessage
+     * @return \Grpc\UnaryCall
      */
     public function Start(\Grpc\Testing\ReconnectParams $argument,
       $metadata = [], $options = []) {
@@ -53,7 +53,7 @@
      * @param \Grpc\Testing\EmptyMessage $argument input argument
      * @param array $metadata metadata
      * @param array $options call options
-     * @return \Grpc\Testing\ReconnectInfo
+     * @return \Grpc\UnaryCall
      */
     public function Stop(\Grpc\Testing\EmptyMessage $argument,
       $metadata = [], $options = []) {
diff --git a/src/php/tests/interop/Grpc/Testing/TestServiceClient.php b/src/php/tests/interop/Grpc/Testing/TestServiceClient.php
index 770c609..f2859fe 100644
--- a/src/php/tests/interop/Grpc/Testing/TestServiceClient.php
+++ b/src/php/tests/interop/Grpc/Testing/TestServiceClient.php
@@ -41,7 +41,7 @@
      * @param \Grpc\Testing\EmptyMessage $argument input argument
      * @param array $metadata metadata
      * @param array $options call options
-     * @return \Grpc\Testing\EmptyMessage
+     * @return \Grpc\UnaryCall
      */
     public function EmptyCall(\Grpc\Testing\EmptyMessage $argument,
       $metadata = [], $options = []) {
@@ -56,7 +56,7 @@
      * @param \Grpc\Testing\SimpleRequest $argument input argument
      * @param array $metadata metadata
      * @param array $options call options
-     * @return \Grpc\Testing\SimpleResponse
+     * @return \Grpc\UnaryCall
      */
     public function UnaryCall(\Grpc\Testing\SimpleRequest $argument,
       $metadata = [], $options = []) {
@@ -73,7 +73,7 @@
      * @param \Grpc\Testing\SimpleRequest $argument input argument
      * @param array $metadata metadata
      * @param array $options call options
-     * @return \Grpc\Testing\SimpleResponse
+     * @return \Grpc\UnaryCall
      */
     public function CacheableUnaryCall(\Grpc\Testing\SimpleRequest $argument,
       $metadata = [], $options = []) {
@@ -89,7 +89,7 @@
      * @param \Grpc\Testing\StreamingOutputCallRequest $argument input argument
      * @param array $metadata metadata
      * @param array $options call options
-     * @return \Grpc\Testing\StreamingOutputCallResponse
+     * @return \Grpc\ServerStreamingCall
      */
     public function StreamingOutputCall(\Grpc\Testing\StreamingOutputCallRequest $argument,
       $metadata = [], $options = []) {
@@ -104,7 +104,7 @@
      * The server returns the aggregated size of client payload as the result.
      * @param array $metadata metadata
      * @param array $options call options
-     * @return \Grpc\Testing\StreamingInputCallResponse
+     * @return \Grpc\ClientStreamingCall
      */
     public function StreamingInputCall($metadata = [], $options = []) {
         return $this->_clientStreamRequest('/grpc.testing.TestService/StreamingInputCall',
@@ -118,7 +118,7 @@
      * demonstrates the idea of full duplexing.
      * @param array $metadata metadata
      * @param array $options call options
-     * @return \Grpc\Testing\StreamingOutputCallResponse
+     * @return \Grpc\BidiStreamingCall
      */
     public function FullDuplexCall($metadata = [], $options = []) {
         return $this->_bidiRequest('/grpc.testing.TestService/FullDuplexCall',
@@ -133,7 +133,7 @@
      * first request.
      * @param array $metadata metadata
      * @param array $options call options
-     * @return \Grpc\Testing\StreamingOutputCallResponse
+     * @return \Grpc\BidiStreamingCall
      */
     public function HalfDuplexCall($metadata = [], $options = []) {
         return $this->_bidiRequest('/grpc.testing.TestService/HalfDuplexCall',
@@ -147,7 +147,7 @@
      * @param \Grpc\Testing\EmptyMessage $argument input argument
      * @param array $metadata metadata
      * @param array $options call options
-     * @return \Grpc\Testing\EmptyMessage
+     * @return \Grpc\UnaryCall
      */
     public function UnimplementedCall(\Grpc\Testing\EmptyMessage $argument,
       $metadata = [], $options = []) {
diff --git a/src/php/tests/interop/Grpc/Testing/UnimplementedServiceClient.php b/src/php/tests/interop/Grpc/Testing/UnimplementedServiceClient.php
index 9988a6c..6c50962 100644
--- a/src/php/tests/interop/Grpc/Testing/UnimplementedServiceClient.php
+++ b/src/php/tests/interop/Grpc/Testing/UnimplementedServiceClient.php
@@ -41,7 +41,7 @@
      * @param \Grpc\Testing\EmptyMessage $argument input argument
      * @param array $metadata metadata
      * @param array $options call options
-     * @return \Grpc\Testing\EmptyMessage
+     * @return \Grpc\UnaryCall
      */
     public function UnimplementedCall(\Grpc\Testing\EmptyMessage $argument,
       $metadata = [], $options = []) {
diff --git a/src/php/tests/interop/Grpc/Testing/XdsUpdateHealthServiceClient.php b/src/php/tests/interop/Grpc/Testing/XdsUpdateHealthServiceClient.php
index 4450dd7..9715493 100644
--- a/src/php/tests/interop/Grpc/Testing/XdsUpdateHealthServiceClient.php
+++ b/src/php/tests/interop/Grpc/Testing/XdsUpdateHealthServiceClient.php
@@ -39,7 +39,7 @@
      * @param \Grpc\Testing\EmptyMessage $argument input argument
      * @param array $metadata metadata
      * @param array $options call options
-     * @return \Grpc\Testing\EmptyMessage
+     * @return \Grpc\UnaryCall
      */
     public function SetServing(\Grpc\Testing\EmptyMessage $argument,
       $metadata = [], $options = []) {
@@ -53,7 +53,7 @@
      * @param \Grpc\Testing\EmptyMessage $argument input argument
      * @param array $metadata metadata
      * @param array $options call options
-     * @return \Grpc\Testing\EmptyMessage
+     * @return \Grpc\UnaryCall
      */
     public function SetNotServing(\Grpc\Testing\EmptyMessage $argument,
       $metadata = [], $options = []) {