replica_exists
Returns true if the replica already exists / has been initialized. Returns false otherwise.
_file_exists PATH
Returns true if PATH is a file or directory in this replica's directory structure
traverse_changesets { after => SEQUENCE_NO, callback => sub { } }
Walks through all changesets from $after to $until, calling $callback on each.
If no $until is specified, the latest changeset is assumed.
read_userdata_file
Returns the contents of the given file in this replica's userdata directory. Returns "undef" if the file does not exist.
write_userdata
Writes the given string to the given file in this replica's userdata directory.