Snakemake throws an error for configs that use null value for bx_whitelist. The Snakefile is testing for empty string, which doesn't play nicely with null.
WorkflowError in line 116 of /Users/mfansler/mayrlab/git/scUTRquant/Snakefile:
Function did not return str or list of str.
Snakemake throws an error for configs that use
nullvalue forbx_whitelist. The Snakefile is testing for empty string, which doesn't play nicely with null.