refactor(lib): resolve unused warning #2189

Job	Run time
Verify hyper.h is up to date	58s
Check Style	19s
Check MSRV	4m 52s
features	33s
Test C API (FFI)	54s
Test with Miri	1m 19s
Test stable on ubuntu-latest	2m 15s
udeps	35s
Test stable on windows-latest	3m 35s
Test stable on macOS-latest	2m 32s
Test beta on ubuntu-latest	1m 53s
Test beta on windows-latest	3m 35s
Test beta on macOS-latest	2m 52s
Test nightly on ubuntu-latest	2m 22s
Test nightly on windows-latest	4m 41s
Test nightly on macOS-latest	1m 44s
Build docs	30s
Check exposed types	26s
CI is green	1s
	35m 56s

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