using LCD bargraph with SRLCD

I've tested each one of these alone, but don't know how to use both...
I want to use these two things:

I tried changing this:

LcdBarGraph lbg(&lcd, DISPLAY_WIDTH);  //LCD Bargraph

to this:

LcdBarGraph lbg(&srlcd, DISPLAY_WIDTH);  //LCD Bargraph

...with no luck.
To use both of these, would the bargraph.h library have to be editted to make it work with srlcd.h, instead of liquidcrystal.h?
It looks over my head.