tesing
   =======================

   ```{r echo=FALSE,results='asis'}
   mytest <- function(myresponse, myterms, mydata) {
     # do clever stuff...
     # then:
     plot1 <- barplot(ppr$pain_protocol1, name=ppr$category,las=2)
     plot2 <- barplot(ppr_pa$extra_pp, name=ppr_pa$adult_anaesthetist,las=2)
     list(plot1 = plot1, plot2 = plot2)
   }

   terms <- c(' age', 'log_age', 'age2', 'inv_age', 'op_time', 'log_op_time',
       'op_time2', 'gender', 'category', 'thimble')
   response <- 'pain_protocol1'
   results <- mytest(response, terms, d4)

   ```

This is plot 1:

  ```{r echo=FALSE,results='asis'}
  library(ggplot2)
  ggplot_build(results[["plot1"]])
  ```

  This is plot 2:

  ```{r echo=FALSE,results='asis'}
  results[["plot2"]]
  ```