.
:param require_save: if this is true, then not saving in the editor
                     will make the return value become `None`.
:param extension: the extension to tell the editor about.  This defaults
                  to `.txt` but changing this might change syntax
                  highlighting.
:param filename: if provided it will edit this file instead of the
                 provided text contents.  It will not use a temporary
                 file as an indirection in that case. If the editor supports
                 editing multiple files at once, a sequence of files may be
                 passed as well. Invoke `click.file` once per file instead
                 if multiple files cannot be managed at once or editing the
                 files serially is desired.

.. versionchanged:: 8.2.0
    ``filename`` now accepts any ``Iterable[str]`` in addition to a ``str``
    if the ``editor`` supports editing multiple files at once.

r