@Override
  public SourceVersion getSupportedSourceVersion() {
    return SourceVersion.latestSupported();
  }
Maps the class names of service provider interfaces to the class names of the concrete classes
which implement them.

<p>For example, {@code "com.google.apphosting.LocalRpcService" ->
"com.google.apphosting.datastore.LocalDatastoreService"}
service/processor/src/main/java/com/google/auto/service/processor/AutoServiceProcessor.java