Dataset class

A dataset is a Blosc2-encoded file on a root repository (thus a File) representing either a flat string of bytes or an n-dimensional array.

Dataset(name, root, host)	A dataset is a Blosc2 container in a file.
Dataset.__getitem__(slice_)	Get a slice of the dataset.
Dataset.get_download_url()	Get the download URL for a file.
Dataset.fetch([slice_, prefer_schunk])	Fetch a slice of a dataset.
Dataset.download()	Download a file.
Dataset.vlmeta	Access variable-length metalayers (i.e. user attributes) for a file.