title: Merging two y-axes titles in patchwork
body: <p>Any ideas as to how I can &quot;merge&quot; two identical y-axes titles into one, and then place this y-axis title in the middle between the plot? I have succeded in merging legends by using  <code>plot_layout(guides = &quot;collect&quot;)</code> but I cannot seem to find anything similar for axes. In this case I would merge the two axes titles called disp_disp_disp into one.</p>
  <p><a href="https://i.stack.imgur.com/4ulkY.png" rel="noreferrer"><img src="https://i.stack.imgur.com/4ulkY.png" alt="enter image description here" /></a></p>
  <pre><code>mtcars
  
  library(ggplot2)
  library(patchwork)
  
  p1 &lt;- ggplot(mtcars) + 
    geom_point(aes(mpg, disp)) + 
    labs(x = &quot;mpg&quot;, y = &quot;disp_disp_disp_disp_disp&quot;)
  
  p2 &lt;- ggplot(mtcars) + 
    geom_boxplot(aes(gear, disp, group = gear)) + 
    labs(x = &quot;gear&quot;, y = &quot;disp_disp_disp_disp_disp&quot;)
  
  p3 &lt;- ggplot(mtcars) + 
    geom_point(aes(hp, wt, colour = mpg)) + 
    ggtitle('Plot 3')
  
  p1 / (p2 | p3)
  </code></pre>