feat(lib): missing Timer will warn or panic #2292

Job	Run time
Verify hyper.h is up to date	25s
Check Style	5s
features	11s
Test C API (FFI)	47s
Test with Miri	1m 24s
Check MSRV	1m 47s
Test stable on ubuntu-latest	1m 13s
udeps	23s
Test stable on windows-latest	4m 24s
Test stable on macOS-latest	2m 22s
Test beta on ubuntu-latest	1m 22s
Test beta on windows-latest	3m 9s
Test beta on macOS-latest	2m 17s
Test nightly on ubuntu-latest	1m 16s
Test nightly on windows-latest	3m 20s
Test nightly on macOS-latest	1m 43s
Build docs	14s
Check exposed types	33s
CI is green	0s
	26m 55s

Provide feedback