def get_package_url(cls, package, session=None, silent=False):
        response = get("{}/packages/{}".format(cls.bower_base_uri, package))
        return response.json().get("url", None)
def winding_flux(pos, flux, ax=0):
    """plot flux vs position"""
    if ax == 0:
        ax = plt.gca()
    ax.set_title('Winding Flux / Vs')
    ax.grid(True)
    for p, f in zip(pos, flux):
        ax.plot(p, f)