Package clique implements the proof-of-authority consensus engine.

Copyright 2018 The Spectrum Authors.

ErrFutureBlock is returned when a block's timestamp is in the future according to the current node.

ErrInvalidNumber is returned if a block's number doesn't equal it's parent's plus one.

ErrUnknownAncestor is returned when validating a block requires an ancestor that is unknown.

ChainReader defines a small collection of methods needed to access the local blockchain during header and/or uncle verification.

Engine is an algorithm agnostic consensus engine.

PoW is a consensus engine based on proof-of-work.