gofumpt (https://github.com/mvdan/gofumpt) provides a supserset of `gofmt` / `go fmt`,
and addresses various formatting issues that linters may be checking for.
We can consider enabling the `gofumpt` linter to verify the formatting in CI, although
not every developer may have it installed, so for now this runs it once to get formatting
in shape.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
1. when lookup an entry which is missing, it should say NotFound.
2. when add duplicated entry, the entries size should be increased.
3. when add entry which has different algorithm, it should be allowed.
Signed-off-by: zhouhaibing089 <zhouhaibing089@gmail.com>
