code: public com.google.protobuf.ByteString
        getAudiencesBytes() {
      java.lang.Object ref = audiences_;
      if (ref instanceof java.lang.String) {
        com.google.protobuf.ByteString b = 
            com.google.protobuf.ByteString.copyFromUtf8(
                (java.lang.String) ref);
        audiences_ = b;
        return b;
      } else {
        return (com.google.protobuf.ByteString) ref;
      }
    }
docs: <pre>
  The list of JWT
  [audiences](https://tools.ietf.org/html/draft-ietf-oauth-json-web-token-32#section-4.1.3).
  that are allowed to access. A JWT containing any of these audiences will
  be accepted. When this setting is absent, only JWTs with audience
  "https://[Service_name][google.api.Service.name]/[API_name][google.protobuf.Api.name]"
  will be accepted. For example, if no audiences are in the setting,
  LibraryService API will only accept JWTs with the following audience
  "https://library-example.googleapis.com/google.example.library.v1.LibraryService".
  Example:
  audiences: bookstore_android.apps.googleusercontent.com,
  bookstore_web.apps.googleusercontent.com
  </pre>
  
  <code>string audiences = 4;</code>