code: def command_update(self):
          
          if len(self.args) == 1 and self.args[0] == "update":
              Update().repository(only="")
          elif (len(self.args) == 2 and self.args[0] == "update" and
                  self.args[1].startswith("--only=")):
              repos = self.args[1].split("=")[-1].split(",")
              for rp in repos:
                  if rp not in self.meta.repositories:
                      repos.remove(rp)
              Update().repository(repos)
          else:
              usage("")
docs: Update package lists repositories