bootstrap

type Helper interface {
	// GenesisBlock should return the genesis block required to bootstrap
	// the ledger (be it reading from the filesystem, generating it, etc.)
	GenesisBlock() *ab.Block
}

type Replacer interface {
	// ReplaceGenesisBlockFile should first copy the current file to a backup
	// file: <genesis-file-name> => <genesis-file-name>.bak
	// and then overwrite the original file with the content of the given block.
	// If something goes wrong during migration, the original file could be
	// restored from the backup.
	// An error is returned if the operation was not completed successfully.
	ReplaceGenesisBlockFile(block *ab.Block) error

	// CheckReadWrite checks whether the current file is readable and writable,
	// because if it is not, there is no point in attempting to replace. This
	// check is performed at the beginning of the consensus-type migration
	// process.
	// An error is returned if the file is not readable and writable.
	CheckReadWrite() error
}