def feature_lyr_osr(feature_lyr):
    """Return the spatial reference of a feature layer

    Parameters
    ----------
    feature_lyr (:class:`ogr.Layer`):
        OGR feature layer from which you desire the :class:`osr.SpatialReference`.

    Returns
    -------
    osr.SpatialReference: the :class:`osr.SpatialReference` object
        of the input feature layer

    """
    return feature_lyr.GetSpatialRef()
