def topo(tess, registrations, properties=None, meta_data=None, chirality=None):
    '''
    topo(tess, regs) yields a Topology object with the given tesselation object tess and the given
      registration map regs.
    '''
    return Topology(tess, registrations, properties=properties, meta_data=meta_data,
                    chirarality=chirality)
topo(tess, regs) yields a Topology object with the given tesselation object tess and the given
      registration map regs.