Plot two functions in the same graph r mirt

Question

I estimated two marginal reliability by using mirt package for two different IRT Graded Response Models. However, I would like to visualized them in the same graph.

#Marginal Reliability of polytomous ModF1
MreliabF1<- marginal_rxx(POLY.MODf1)
plot(POLY.MODf1 = 'rxx', theta_lim = c(-3, 3), 
    main="" )
#Marginal Reliability of ModF2
MreliabF2<- marginal_rxx(POLY.MODf2)
plot(POLY.MODf2, type = 'rxx', theta_lim = c(-3, 3), 
     main="" )

These syntax help me to generate two graph separately.

How can I combine them? Could ExtraLattice be a useful package?