How to trim curves in GhPython

hello everybody
I can’t figure out how to trim a curve in GhPython.
Because there is no command in rhinoscriptsyntax to trim curves.
How can I trim curves in GhPython?
I want to trim spiral_curve with FilletedCurve.
TrimCurve.gh (21.7 KB)

You can implement Curve.Trim :

Sorry.
My explanation was incorrect.

If you mean split there is rs.SplitCurve

split curve.gh (24.5 KB)

That is exactly what I want to do.
I’m sorry I can’t explain it better.
Thank you very much.