{{alias}}()
    Returns the effective numeric group identity of the calling process.

    The function only returns an effective group identity on POSIX platforms.
    For all other platforms (e.g., Windows and Android), the function returns
    `null`.

    Returns
    -------
    id: integer|null
        Effective numeric group identity.

    Examples
    --------
    > var gid = {{alias}}()

    See Also
    --------