* use increment and decrement operators.
* remove unnecessary else branches.
* fix package comment with leading space.
* fix receiver names.
* fix error strings.
* remove omittable code.
* remove redundant return statement.
* Revert changes (code is generated.)
* use cfg as receiver name for all config-related types.
* use lsi as the receiver name for the LastSignedInfo type.
* Full test PeerSet and check its concurrent guarantees
* Improve the doc for PeerSet.Has and remove unnecessary
defer for a path that sets a variable, make it fast anyways.
* Parallelize PeerSet tests with t.Parallel()
* Document functions in peer_set.go more.