040000 tree 53e8f71a3a6fb5900843119bd1f630a573b132c6	greeter_client
040000 tree f11d2017f12b6396add7e632c001f6bb1db70c7e	greeter_server
040000 tree 3317cb4bb9a39793b9c5f15efacd47d80696572f	helloworld
040000 tree 0ecf9c3f0b19eabe209434eea22bf49cb53dafec	mock_helloworld