old_contents: from wfdb.io import _url
  
  
  def _open_file(
      pn_dir,
      file_name,
      mode="r",
      *,
      buffering=-1,
      encoding=None,
      errors=None,
      newline=None,
      check_access=False,
  ):
      """
      Open a data file as a random-access file object.
  
      See the documentation of `open` and `wfdb.io._url.openurl` for details
      about the `mode`, `buffering`, `encoding`, `errors`, and `newline`
      parameters.
  
      Parameters
      ----------
      pn_dir : str or None
          The PhysioNet database directory where the file is stored, or None
          if file_name is a local path.
      file_name : str
          The name of the file, either as a local filesystem path (if
          `pn_dir` is None) or a URL path (if `pn_dir` is a string.)
      mode : str, optional
          The standard I/O mode for the file ("r" by default).  If `pn_dir`
          is not None, this must be "r", "rt", or "rb".
      buffering : int, optional
          Buffering policy.
      encoding : str, optional
          Name of character encoding used in text mode.
      errors : str, optional
          Error handling strategy used in text mode.
      newline : str, optional
          Newline translation mode used in text mode.
      check_access : bool, optional
          If true, raise an exception immediately if the file does not
          exist or is not accessible.
  
      """
      if pn_dir is None:
          return open(
              file_name,
              mode,
              buffering=buffering,
              encoding=encoding,
              errors=errors,
              newline=newline,
          )
      else:
          url = posixpath.join(config.db_index_url, pn_dir, file_name)
          return _url.openurl(
              url,
              mode,
              buffering=buffering,
              encoding=encoding,
              errors=errors,
              newline=newline,
              check_access=check_access,
          )
  
new_contents: import posixpath
  
  from wfdb.io import _url
  
  
  def _open_file(
      pn_dir,
      file_name,
      mode="r",
      *,
      buffering=-1,
      encoding=None,
      errors=None,
      newline=None,
      check_access=False,
  ):
      """
      Open a data file as a random-access file object.
  
      See the documentation of `open` and `wfdb.io._url.openurl` for details
      about the `mode`, `buffering`, `encoding`, `errors`, and `newline`
      parameters.
  
      Parameters
      ----------
      pn_dir : str or None
          The PhysioNet database directory where the file is stored, or None
          if file_name is a local path.
      file_name : str
          The name of the file, either as a local filesystem path (if
          `pn_dir` is None) or a URL path (if `pn_dir` is a string.)
      mode : str, optional
          The standard I/O mode for the file ("r" by default).  If `pn_dir`
          is not None, this must be "r", "rt", or "rb".
      buffering : int, optional
          Buffering policy.
      encoding : str, optional
          Name of character encoding used in text mode.
      errors : str, optional
          Error handling strategy used in text mode.
      newline : str, optional
          Newline translation mode used in text mode.
      check_access : bool, optional
          If true, raise an exception immediately if the file does not
          exist or is not accessible.
  
      """
      if pn_dir is None:
          return open(
              file_name,
              mode,
              buffering=buffering,
              encoding=encoding,
              errors=errors,
              newline=newline,
          )
      else:
          url = posixpath.join(config.db_index_url, pn_dir, file_name)
          return _url.openurl(
              url,
              mode,
              buffering=buffering,
              encoding=encoding,
              errors=errors,
              newline=newline,
              check_access=check_access,
          )
  
subject: add missing 'import posixpath'.