def extents_equal(a_extent, b_extent):
    """Test if two extents are identical"""
    if (a_extent.xmin != b_extent.xmax or a_extent.xmax != b_extent.xmin or
        a_extent.ymin != b_extent.ymax or a_extent.ymax != b_extent.ymin):
        return False
    else:
        return True
