docs: public String getNameForBackend(SoyBackendKind backend) {
      switch (backend) {
        case JS_SRC:
          // The 'proto' prefix is JSPB-specific. If we ever support some other
          // JavaScript proto implementation, we'll need some way to determine which
          // proto implementation the user wants to use at this point.
          return ProtoUtils.calculateQualifiedJsName(typeDescriptor);
        case TOFU:
        case JBC_SRC:
          return JavaQualifiedNames.getClassName(typeDescriptor);
        case PYTHON_SRC:
          throw new UnsupportedOperationException();
      }
      throw new AssertionError(backend);
    }