prepareBatchBody method
Prepares the batch body bytes for sending.
Override this for custom serialization (e.g., gzip compression). The default implementation JSON-encodes the batch.
Returns a record with body bytes and optional extra headers.
Implementation
Future<({List<int> body, Map<String, String> extraHeaders})> prepareBatchBody(
List<Map<String, dynamic>> batch,
) async {
final jsonBody = jsonEncode(batch);
return (body: utf8.encode(jsonBody), extraHeaders: <String, String>{});
}