newMultipartRequest method
Constructs a new MultipartRequest that will use this client to send the request. Throws a StateError if this client has been closed.
Implementation
@override
MultipartRequest newMultipartRequest() {
verifyNotClosed();
// ignore: deprecated_member_use_from_same_package
final request = MockMultipartRequest.fromClient(this, _transport);
registerAndDecorateRequest(request);
return request;
}