Writes the network object given as "inpNET" as a .str file readable by PHEM.
    Returns a map from the SUMO-road id to the generated numerical id used by PHEM.

    The following may be a matter of changes:
    - currently, only the positions of the start and the end nodes are written,
      the geometry of the edge as defined in the SUMO-network is not exported.
      A map between the edge id and a segment to a numerical id would be necessary

def net2str(net, outSTRM):
    """
    Writes the network object given as "inpNET" as a .str file readable by PHEM.
    Returns a map from the SUMO-road id to the generated numerical id used by PHEM.

    The following may be a matter of changes:
    - currently, only the positions of the start and the end nodes are written,
      the geometry of the edge as defined in the SUMO-network is not exported.
      A map between the edge id and a segment to a numerical id would be necessary
    """
    if outSTRM is not None:
        print("Str-Id,Sp,SegAnX,SegEnX,SegAnY,SegEnY", file=outSTRM)
    sIDm = sumolib._Running()
    for e in net._edges:
        eid = sIDm.g(e._id)
        if outSTRM is not None:
            c1 = e._from._coord
            c2 = e._to._coord
            print("%s,%s,%s,%s,%s,%s" %
                  (eid, len(e._lanes), c1[0], c2[0], c1[1], c2[1]), file=outSTRM)
    return sIDm