Run a set of diagnostic plots. Note that for this function to
    work, est_ce must be run with return_extras=T.
     
    
    
    Arguments
- obj
 
An object of class vaccine_est returned by
est_ce
 
 
    
    Value
    A combined plot of model diagnostics
     
    
    Examples
    data(hvtn505)
dat <- load_data(time="HIVwk28preunblfu", event="HIVwk28preunbl", vacc="trt",
                 marker="IgG_V2", covariates=c("age","BMI","bhvrisk"),
                 weights="wt", ph2="casecontrol", data=hvtn505)
# \donttest{
ests_np <- est_ce(dat=dat, type="NP", t_0=578, return_extras=TRUE)
diagnostics(ests_np)
# }