sliceCode
The slice codes depend on what slice you select. For example, if you select the "area" slice,
your sliceCode should be a FIPS code. If you select "industry," your sliceCode should be a NIACS code.
There are three internal data sets containing acceptable slice codes to help with selections; blscrapeR::niacs
contains industry codes and descriptions, blscrapeR::area_titles contains FIPS codes and area descriptions,
and blscrapeR::size_titles contains industry size codes. These codes can be used for the sliceCode argument.