message: Return an error in the SignaturePemKeysetReaderBuilder in case the pem_reader_type_ is not known.
diff: @@ -315,6 +315,8 @@ SignaturePemKeysetReaderBuilder::Build() {
  new PublicKeyVerifyPemKeysetReader(pem_serialized_keys_));
  }
  }
  + return util::Status(util::error::INVALID_ARGUMENT,
  + "Unknown pem_reader_type_");
  }
  util::StatusOr<std::unique_ptr<Keyset>> PublicKeySignPemKeysetReader::Read() {
  