DoubleVote denotes a slashable offense in which a validator cast two conflicting attestations within the same target epoch.

SurroundVote denotes a slashable offense in which a validator surrounded or was surrounded by a previous attestation created by the same validator.

DetectionResult tells us the kind of slashable offense found from detecting on min-max spans + the slashable epoch for the offense.

Span defines the structure used for detecting surround and double votes.

DetectionKind defines an enum type that gives us information on the type of slashable offense found when analyzing validator min-max spans.