code: def save(self, output: Union[str, BinaryIO], series: Optional[str] = None,
               deps: Iterable=tuple(), create_missing_dirs: bool=True) -> "Model":
          
          check_license(self.license)
          if series is None:
              if self.series is None:
                  raise ValueError("series must be specified")
          else:
              self.series = series
          if isinstance(output, str) and create_missing_dirs:
              dirs = os.path.split(output)[0]
              if dirs:
                  os.makedirs(dirs, exist_ok=True)
          self.set_dep(*deps)
          tree = self._generate_tree()
          self._write_tree(tree, output)
          self._initial_version = self.version
          return self
docs: Serialize the model to a file.
  
          :param output: Path to the file or a file object.
          :param series: Name of the model series. If it is None, it will be taken from \
                         the current value; if the current value is empty, an error is raised.
          :param deps: List of the dependencies.
          :param create_missing_dirs: create missing directories in output path if the output is a \
                                      path.
          :return: self