Missing exception in chunk_dataset() #1159
Description
Describe the bug
chunk_dataset() has a parameter 'format' with the two valid options "zarr" and "netcdf4", which determines the encoding of the data variables to be chunked for the target file format. This works fine for the two possible values of the parameter but the function does not update the encoding at all, if parameter value has any other arbitrary value.
To Reproduce
Just use chunk_dataset() with any invalid value for the format parameter.
Expected behavior
If an invalid parameter value is used for format, an instructive exception would be expected.
Screenshots
see above.
Additional context
