@Nullable
  private static <P extends JpsElement> JpsModuleSourceRootPropertiesSerializer<P> getSerializer(JpsModuleSourceRootType<P> type) {
    if (type instanceof UnknownSourceRootType) {
      return (JpsModuleSourceRootPropertiesSerializer<P>)UnknownSourceRootPropertiesSerializer.forType((UnknownSourceRootType)type);
    }
    for (JpsModelSerializerExtension extension : JpsModelSerializerExtension.getExtensions()) {
      for (JpsModuleSourceRootPropertiesSerializer<?> serializer : extension.getModuleSourceRootPropertiesSerializers()) {
        if (serializer.getType().equals(type)) {
          return (JpsModuleSourceRootPropertiesSerializer<P>)serializer;
        }
      }
    }
    return null;
  }
@Nullable
  private static <P extends JpsElement> JpsModuleSourceRootPropertiesSerializer<P> getSerializer(JpsModuleSourceRootType<P> type)