GatherForks gathers all the known forks and creates a sorted list out of them.

NewFilterFromForks creates a filter that returns if a fork ID should be rejected or not based on the provided current head.

NewStaticFilter creates a filter at block zero.

ErrLocalIncompatibleOrStale is returned by the validator if a remote fork checksum does not match any local checksum variation, signalling that the two chains have diverged in the past at some point (possibly at genesis).

ErrRemoteStale is returned by the validator if a remote fork checksum is a subset of our already applied forks, but the announced next fork block is not on our already passed chain.

ID is a fork identifier as defined by EIP-2124.

Filter is a fork id filter to validate a remotely advertised ID.