[Rivet] histogram legend with spaces and other characters

[Raghav Kunnawalkam Elayavalli]

Hi Rivet Experts, 

Its me again :) 

I have a question regarding histogram legends in the plot. At the moment, if we dont give a specific title, then the name of the yoda file is taken as the legend. Even if i try to give a different title, it has to be one without any spaces or special characters. for example i have a histogram that i ideally want to label 
0-20%, w/ recoils
but this wont get accepted now and make-plots just crashes. I have to say it like so 0_20_wRecoils and that works. Is there a way i can give my custom legend to the histogram. I see that you can give a custom legend in the make plot documentation page, but it looks like its only for the plot as opposed to a specific histogram? 

Cheers
Raghav