def is_colorbar(ax):
    """Detect whether a matplotlib axis contains a colorbar
    Depends on the assumption that colorbar axes are not navigable (i.e. cannot be panned or zoomed in the
    interactive figure).
    
    Inputs:
        * ax (object) - matplotlib axis object 
    """
    not_colorbar = ax.get_navigate()
    return not not_colorbar
