[Kwant] Plot onsite energy using kwant.plot

[Khani Hosein]

Dear all,
I find in the discussion list that we can use kwant.plot to plot the
hopping strength,
def hopping_strength(site1, site2):
    return sys.hamiltonian(site1, site2)
kwant.plot(sys, hop_lw=hopping_strength)
Can we plot the onsite energy of the system similarly?
Regards
Khani Hosein