title: Changing the legend of a figure so that various lines share the same legend entry
body: <p>A colleague has passed me a <code>.fig</code> file that has many lines on the same plots and they are coloured based on which group they belong to. The figure is shown below for reference.</p>
  
  <p>I need to change the legend so that lines with the same colour have the same legend entry. The problem is that I don't have access to the raw data so I can't use the method mentioned <a href="https://stackoverflow.com/questions/2141403/legend-for-group-of-lines">here</a> so is there a way to change the legend entries just using the <code>.fig</code> file? I tried changing some of the legend names to <code>NaN</code> in the property inspector but that just changes the entries to NaN.</p>
  
  <p><a href="https://i.stack.imgur.com/AQ7Ol.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/AQ7Ol.png" alt="What I have so far"></a></p>