[Kwant] Updating Kwant paper and APS tutorials code

Dear all, I am just a beginner on Kwant and downloaded Kwant 1.4. It is quite frustrated on getting syntax errors using full sample code from Kwan paper or APS tutorial which themselves provide very good introduction. For example, in Kwant paper Appendix D.5, smatrix = kwant.smatrix(sys, energy, args=[phi, ""]) doesn't work. Then I have modified to smatrix = kwant.smatrix(sys, energy,params=(phi=phi,salt="" ) it still doesn't work. Could anyone help? There are so many codes in Kwant paper and APS tutorial which relies on old version of Kwant. It would really be very helpful to keep the sample codes updated. Thanks a lot. Clement