code: def _cwlvar_to_wdl(var):
      
      if isinstance(var, (list, tuple)):
          return [_cwlvar_to_wdl(x) for x in var]
      elif isinstance(var, dict):
          assert var.get("class") == "File", var
          # XXX handle secondary files
          return var.get("path") or var["value"]
      else:
          return var
docs: Convert a CWL output object into a WDL output.
  
      This flattens files and other special CWL outputs that are
      plain strings in WDL.