This dataset fills a buffer with `buffer_size` elements, then randomly samples elements from this buffer,
        replacing the selected elements with new elements. For perfect shuffling, a buffer size greater than or
        equal to the full size of the dataset is required.

        For instance, if your dataset contains 10,000 elements but `buffer_size` is set to 1000, then `shuffle` will
        initially select a random element from only the first 1000 elements in the buffer. Once an element is
        selected, its space in the buffer is replaced by the next (i.e. 1,001-st) element,
        maintaining the 1000 element buffer.

        If the dataset is made of several shards, it also does shuffle the order of the shards.
        However if the order has been fixed by using [`~datasets.IterableDataset.skip`] or [`~datasets.IterableDataset.take`]
        then the order of the shards is kept unchanged.