Testing in flutter when i have timer

I have a splash screen in my flutter app and after 2 seconds it's navigate automatically to intro page, but when i wrote test for splash screen i got this problem

══╡ EXCEPTION CAUGHT BY FLUTTER TEST FRAMEWORK ╞════════════════════════════════════════════════════
The following assertion was thrown running a test:
A Timer is still pending even after the widget tree was disposed.

and many errors so.