title: Datatable is not printed in combination with cat command in Rmd / RStudio
body: <p>Could someone please explain why in the Rmd code (to generate a HTML report using RStudio) below only the <code>cat</code> command is being displayed? When I move the <code>cat</code> command outside the <code>if</code> clause or comment it out the table is printed. I believe the same thing happens when using <code>library(printr)</code>, but I haven't confirmed this with a minimal sample.</p>
  
  <p>It seems that the code inside the <code>if</code> clause is somehow interpreted together and that the <code>cat</code> doesn't go well with the <code>datatable</code>.</p>
  
  <p>If you could give me some clues on how to debug this, it would be helpful, too. As there are no warnings/error messages anywere.</p>
  
  <pre><code>---
  title: "test"
  output: 
    html_document
  ---
  
  
  ```{r}
  if(TRUE){
    DT::datatable(iris)
    cat("I am here with my cat")
  }
  
  ```
  </code></pre>