### 21.1.2.4 The Catalog constructor

GNOME uses a version of the `gettext` module by James Henstridge, but this version has a slightly different API. Its documented usage was:

    import gettext
    cat = gettext.Catalog(domain, localedir)
    _ = cat.gettext
    print _('hello world')

For compatibility with this older module, the function `Catalog()` is an alias for the `translation()` function described above.

One difference between this module and Henstridge's: his catalog objects supported access through a mapping API, but this appears to be unused and so is not currently supported.