code: @Deprecated
    @SuppressWarnings("unused") // called through reflection by RequestServer
    public MetadataV3 fetchSchemaMetadataByClass(int version, MetadataV3 docs) {
      docs.schemas = new SchemaMetadataV3[1];
      // NOTE: this will throw an exception if the classname isn't found:
      SchemaMetadataV3 meta = new SchemaMetadataV3(SchemaMetadata.createSchemaMetadata(docs.classname));
      docs.schemas[0] = meta;
      return docs;
    }
docs: Fetch the metadata for a Schema by its full internal classname, e.g. "hex.schemas.DeepLearningV2.DeepLearningParametersV2".  TODO: Do we still need this?