many fix and more assert #20

Job	Run time
test stable --no-default-features	54s
test stable	54s
test stable --features="all, scroll"	1m 33s
test stable --features="all, optimism"	1m 26s
test beta --no-default-features	1m 1s
test beta	55s
test beta --features="all, scroll"	1m 24s
test beta --features="all, optimism"	1m 28s
test no_std	35s
test nightly --no-default-features	2m 18s
test nightly	2m 12s
check no-default-features	20s
test nightly --features="all, scroll"	2m 10s
test nightly --features="all, optimism"	2m 14s
check serde	19s
check std	29s
clippy	2m 24s
docs	1m 4s
fmt	7s
	23m 47s

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