How to use the immutabledict.immutabledict function in immutabledict

save_when = SaveWhen.ALWAYS

    # Instructions how to parallelize
    #   False: never parallellize;
    #   'process': use processpool;
    #   'thread' (or just True): use threadpool.
    parallel = False              # For the computation itself

    # Maximum number of output messages
    max_messages = None   # use default

    # Do not specify attributes below

    # Set using the takes_config decorator
    takes_config = immutabledict()

    # These are set on plugin initialization, which is done in the core
    run_id: str
    run_i: int
    config: typing.Dict
    deps: typing.Dict       # Dictionary of dependency plugin instances
    
    compute_takes_chunk_i = False    # Autoinferred, no need to set yourself
    compute_takes_start_end = False

    def __init__(self):
        if not hasattr(self, 'depends_on'):
            raise ValueError('depends_on not provided for '
                             f'{self.__class__.__name__}')

        self.depends_on = strax.to_str_tuple(self.depends_on)

result[opt.name] = opt

        # For some reason the second condition is essential, I don't understand
        # yet why...
        if (hasattr(plugin_class, 'takes_config')
                and len(plugin_class.takes_config)):
            # Already have some options set, e.g. because of subclassing
            # where both child and parent have a takes_config decorator
            for opt in result.values():
                if opt.name in plugin_class.takes_config:
                    raise RuntimeError(
                        f"Attempt to specify option {opt.name} twice")
            plugin_class.takes_config = immutabledict({
                **plugin_class.takes_config, **result})
        else:
            plugin_class.takes_config = immutabledict(result)
        return plugin_class

if not isinstance(opt, Option):
                raise RuntimeError("Specify config options by Option objects")
            opt.taken_by = plugin_class.__name__
            result[opt.name] = opt

        # For some reason the second condition is essential, I don't understand
        # yet why...
        if (hasattr(plugin_class, 'takes_config')
                and len(plugin_class.takes_config)):
            # Already have some options set, e.g. because of subclassing
            # where both child and parent have a takes_config decorator
            for opt in result.values():
                if opt.name in plugin_class.takes_config:
                    raise RuntimeError(
                        f"Attempt to specify option {opt.name} twice")
            plugin_class.takes_config = immutabledict({
                **plugin_class.takes_config, **result})
        else:
            plugin_class.takes_config = immutabledict(result)
        return plugin_class

def can_rechunk(self, data_type):
        if isinstance(self.rechunk_on_save, bool):
            return self.rechunk_on_save
        if isinstance(self.rechunk_on_save, (dict, immutabledict)):
            return self.rechunk_on_save[data_type]
        raise ValueError("rechunk_on_save must be a bool or an immutabledict")