func (c *Chain) traceLongestChainTail(blockHeader *types.BlockHeader) (*types.BlockHeader, error) {
longestTail, workQueue := blockHeader, []*types.BlockHeader{blockHeader}
func (c *Chain) traceLongestChainTail(blockHeader *types.BlockHeader) (*types.BlockHeader, error) {
longestTail, workQueue := blockHeader, []*types.BlockHeader{blockHeader}