MutableType       689 third_party/protobuf/src/google/protobuf/extension_set.h   typedef string* MutableType;
MutableType       708 third_party/protobuf/src/google/protobuf/extension_set.h   typedef string* MutableType;
MutableType       783 third_party/protobuf/src/google/protobuf/extension_set.h   typedef Type* MutableType;
MutableType       810 third_party/protobuf/src/google/protobuf/extension_set.h   typedef Type* MutableType;