Method cannot be declared public because its parameter uses an internal type

Please be sure to include:

what OS you are developing on (Linux or macOS, including the version) macos:10.13
for macOS, what version of Xcode you are using (xcodebuild -version), for Linux, what version of Swift (swift --version) xcode10.0
what version of Swift is your code set to compile with (i.e. from project settings, etc.) swift4
what branch/tag of SwiftProtobuf you are using (1.0.0, etc.) 1.1.2
if you are getting compile errors, please be sure include all errors/warnings, sometimes the error before the one you are stuck on is important.
```
Method cannot be declared public because its parameter uses an internal type
```
lastly, if it all possible, provide a snippet of .proto and/or source that shows the problem.
```
message KyStsControl{
int32 eventId =1;
string controlName = 2;
string eventDes = 3;
}
```

struct KyStsControl {
  // SwiftProtobuf.Message conformance is added in an extension below. See the
  // `Message` and `Message+*Additions` files in the SwiftProtobuf library for
  // methods supported on all messages.

  var eventID: Int32 = 0

  var controlName: String = String()

  var eventDes: String = String()

  var unknownFields = SwiftProtobuf.UnknownStorage()

  init() {}
}

Thank you!

apple / swift-protobuf

Method cannot be declared public because its parameter uses an internal type #798