Note: Providing complete information in the most concise form is the best way to get help. This issue template serves as the checklist for essential information to most of the technical issues and bug reports. For non-technical issues and feature requests, feel free to present the information in what you believe is the best form.

For Q & A and discussion, please start a discussion thread at https://discuss.mxnet.io

Description

Transforms are not compatible with _DownloadedDatasets such as MNIST

Environment info (Required)

MAC and Ubuntu 16.04

What to do:
1. Download the diagnosis script from https://raw.githubusercontent.com/apache/incubator-mxnet/master/tools/diagnose.py
2. Run the script using `python diagnose.py` and paste its output here.

Package used (Python/R/Scala/Julia):
(I'm using Python)

Error Message:

TypeError: forward() takes 2 positional arguments but 3 were given

Minimum reproducible example

from mxnet.gluon.data import Dataloader
from mxnet.gluon.vision import transforms, MNIST

ds = MNIST(train=True, transform=transforms.ToTensor)
dl = DataLoader(ds, 10, shuffle=True)

What have you tried to solve it?

the transforms function take one data as input but _DownloadDatasets use datasets and labels as input L201

Also, checked the ImageRecordDataset, it consists with _DownloadedDatasets.
Suggest to change the transform API to forward(F, x, y)