def _get_projection(el):
    """
    Get coordinate reference system from non-auxiliary elements.
    Return value is a tuple of a precedence integer and the projection,
    to allow non-auxiliary components to take precedence.
    """
    result = None
    if hasattr(el, 'crs'):
        result = (int(el._auxiliary_component), el.crs)
    return result
Get coordinate reference system from non-auxiliary elements.
    Return value is a tuple of a precedence integer and the projection,
    to allow non-auxiliary components to take precedence.