Support gated datasets
See https://huggingface.co/datasets/oscar-corpus/OSCAR-2109, https://huggingface.co/datasets/mozilla-foundation/common_voice_1_0

Note: we restrict this issue to the *public* gated datasets.
Support gated datasets: See https://huggingface.co/datasets/oscar-corpus/OSCAR-2109, https://huggingface.co/datasets/mozilla-foundation/common_voice_1_0

Note: we restrict this issue to the *public* gated datasets.