title: extract plots from list R
body: <p>I have made a function:</p>
  <pre><code>mtcars_plot_fun &lt;- function(cyl_in, gear_in) {
    car_data &lt;- mtcars %&gt;%
      filter(cyl == cyl_in,
             gear == gear_in)
    p &lt;- car_data %&gt;% ggplot(aes(x = disp, y = qsec, fill = gear)) +
      geom_point() 
    print(p)
  }
  </code></pre>
  <p>Then a loop that makes plots and stores them in the list object <code>gg_obj</code></p>
  <pre><code>cyls &lt;- c(4, 6)
  
  gears &lt;- c(3, 4)
  
  for (cyl in cyls) {
    for (gear in gears) {
      gg_obj &lt;- mtcars_plot_fun(cyl_in = cyl, gear_in = gear)
      }
  }
  </code></pre>
  <p>Now I want to extract the plots I need from <code>gg_obj</code> and use <code>grid.arrange()</code>, <code>gridExtra</code> or similar to plot them.
  How can I pull out the plots I want, and store them as unique objects to plot in a grid?</p>