OptionalbodyJSON body (object) or pre-serialised string.
OptionalheadersExtra headers. Defaults: Accept: application/json;odata=nometadata,
Content-Type: application/json;odata=verbose when there is a body, and
If-Match: * for PATCH/MERGE/DELETE.
Site-relative REST path starting with _api/, e.g.
_api/web/lists/GetByTitle('Tasks')/items?$top=5, or an absolute URL on
the connection's own origin.
One sub-request of a
$batchcall.