Preview range in Graph Editor. How to set it?!

I realize what i pretty oftenly need to set some preview ranges. Sometimes it would be a range which are already on screen, so all range are displayed on the monitor.
But sometimes range which i need are somewhere left or right and beyond window boundary.
And i dont want to zoom out, set preview range, zoom in again.

I was thinking about simple script where i will automatically make a preview range
ToCursor - preview would start from frame 1 and end on frame where cursor are currently are.
AfterCursor - preview would start from cursor till the end of the animation.

So i just make a random preview range and look what info panel will show and… as example:
bpy.ops.anim.previewrange_set(xmin=717, xmax=1889, ymin=148, ymax=598)

So its basically a screen coordinates which start from 0 at the left bottom corner of the whole graph viewport.

How to deal with this?!