test.introspection=function(){
      t_start=0 
      t_end=10 
      tn=50
      timestep=(t_end-t_start)/tn 
      t=seq(t_start,t_end,timestep) 

      Ex=TwopParallelModel(t,ks=c(k1=0.5,k2=0.2),C0=c(c10=100, c20=150),In=10,gam=0.7,xi=0.5)
      Ct=getC(Ex)
      
      ##demonstrate plot
      plot(Ex)
      ##demonstrate $
      Ex$times
      ##demonstrate  []
      Ex["C"]
      print(Ex[c("times","C","ReleaseFlux","AccumulatedRelease")])
      #demonstrate show
      Ex 
      #demonstrate print
      print(Ex) 
      #demonstrate summary
      summary(Ex) 
}
