code: def Rscript_cmd():
      
      rscript = which(os.path.join(get_bcbio_bin(), "Rscript"))
      if rscript:
          return rscript
      else:
          return which("Rscript")
docs: Retrieve path to locally installed Rscript or first in PATH.
  
      Prefers Rscript version installed via conda to a system version.