Some properties not updated properly

[mattsignorelli]

using AcceleratorLattice
K1 = 0.36
L=0.5
begin0 = BeginningEle("begin0", pc_ref = 1e7, species_ref = Species("electron"))
qf = Quadrupole("qf", Kn1=K1, L=L)
d1 = Drift("d1", L=4.5)
qd = Quadrupole("qd", Kn1=-qf.Kn1, L=qf.L)
d2 = Drift("d2", L=4.5)

lat = Lattice(BeamLine([qf,d1,qd,d2]))

println(qf.Kn1) # fine
println(qf.Bn1) # prints zero

[mattsignorelli]

qd.s also prints zero, is this expected behavior (do I have to run the bookkeeper?)