If a vegaspec has named datasets, it may be useful to rename them.
This function will return a vegaspec with datasets named data_001,
data_002, and so on. It will go through the spec and replace the
references to the names. A future version of this function may give you
the more control over the names used.
vw_rename_datasets(spec)An object to be coerced to vegaspec, a Vega/Vega-Lite specification
S3 object of class vegaspec