code: def uploadFile(uploadfunc, fileindex, existing, uf, skip_broken=False):
      
  
      if uf["location"].startswith("toilfs:") or uf["location"].startswith("_:"):
          return
      if uf["location"] in fileindex:
          uf["location"] = fileindex[uf["location"]]
          return
      if not uf["location"] and uf["path"]:
          uf["location"] = schema_salad.ref_resolver.file_uri(uf["path"])
      if uf["location"].startswith("file://") and not os.path.isfile(uf["location"][7:]):
          if skip_broken:
              return
          else:
              raise cwltool.errors.WorkflowException(
                  "File is missing: %s" % uf["location"])
      uf["location"] = write_file(
          uploadfunc, fileindex, existing, uf["location"])
docs: Update a file object so that the location is a reference to the toil file
      store, writing it to the file store if necessary.