Converts the xarray attrs into args that can be passed into Iris

def _get_iris_args(attrs):
    """ Converts the xarray attrs into args that can be passed into Iris
    """
    # iris.unit is deprecated in Iris v1.9
    import cf_units
    args = {'attributes': _filter_attrs(attrs, iris_forbidden_keys)}
    args.update(_pick_attrs(attrs, ('standard_name', 'long_name',)))
    unit_args = _pick_attrs(attrs, ('calendar',))
    if 'units' in attrs:
        args['units'] = cf_units.Unit(attrs['units'], **unit_args)
    return args