def identity(arg=None, *args):
    """Return the first argument provided to it.

    Args:
        *args (mixed): Arguments.

    Returns:
        mixed: First argument or ``None``.

    Example:

        >>> identity(1)
        1
        >>> identity(1, 2, 3)
        1
        >>> identity() is None
        True

    .. versionadded:: 1.0.0
    """
    return arg
