title: How to plot just the legends in ggplot2?
body: <p>I'm currently working with igraph and have colour labelled my vertices. I would like to add a legend Indicating what each colour represents. </p>
  
  <p>What I can think of at this point is to use ggplot2 to print only the legend and hide a bar plot. 
  Is there a way to just output the legend?</p>