bokeh- Updating the x range start and end on_change

Hi guys,

I have been experimenting with bokeh for a while, but for some reason I am not able to figure out how to update the x-axis range (its start and end points), I know by default it does this, but I want to define the values manually.

NOTE: When I try to define the x_range, it defaults all the updates thereafter to the initial variable’s x_range.start and x_range.end.

Has anyone done this before?