title: Save a list of plots dynamically
body: <p>I am able to generate some plots based on a list of data frames:</p>
  
  <pre><code>df1 &lt;- mtcars
  df2 &lt;- mtcars
  
  combined_mtcars &lt;- list(first_df = df1, second_df = df2)
  
  # make the plots
  imap(.x = combined_mtcars, ~ggplot(.x, aes(x = hp, y = mpg, group = cyl)) +
      geom_line() +
      ggtitle(.y))
  </code></pre>
  
  <p>I wanted to then save each plot to a directory called /plots. So I tried adding ggsave like so:</p>
  
  <pre><code>imap(.x = combined_mtcars, ~ggplot(.x, aes(x = hp, y = mpg, group = cyl)) +
      geom_line() +
      ggtitle(.y)) %&gt;% 
    imap(~ggsave(plot = .y, file = paste0("/plots/", .y, ".png")))
  </code></pre>
  
  <p>This resulted in error "Saving 6.62 x 5.57 in image
  Error in UseMethod("grid.draw") : 
    no applicable method for 'grid.draw' applied to an object of class "character"".</p>
  
  <p>How can I save each iteration where the filename is the same as the title .y?</p>