def __init__(self, config, archiver=None):
if archiver:<EOL><INDENT>self.archivers = [archiver.name]<EOL><DEDENT>else:<EOL><INDENT>self.archivers = cache.list_archivers(config)<EOL><DEDENT>logger.debug(f"<STR_LIT>")<EOL>self.config = config<EOL>self.index = {}<EOL>for archiver in self.archivers:<EOL><INDENT>self.index[archiver] = Index(self.config, resolve_archiver(archiver))<EOL><DEDENT>self.default_archiver = self.archivers[<NUM_LIT:0>]<EOL>
Instantiate a new process state.

:param config: The wily configuration.
:type  config: :class:`WilyConfig`

:param archiver: The archiver (optional).
:type  archiver: :class:`wily.archivers.Archiver`