How to use the haros.visualiser.install function in haros

def _init_haros_dir(self, overwrite=False):
        print "[HAROS] Running setup operations..."
        exists = os.path.exists(self.haros_dir)
        if exists and not os.path.isdir(self.haros_dir):
            raise RuntimeError(("Could not initialise; " + self.haros_dir
                                + " already exists and is not a directory."))
        if not exists:
            self.log.info("Creating %s", self.haros_dir)
            os.makedirs(self.haros_dir)
        self._generate_dir(self.haros_dir, self.DIR_STRUCTURE,
                           overwrite=overwrite)
        if overwrite or not os.path.exists(self.viz_dir):
            viz.install(self.viz_dir, self.run_from_source, force=True, minimal_output=self.minimal_output)
        return True

def _save_results(self, node_cache):
        print "[HAROS] Saving analysis results..."
        if self.export_viz:
            viz.install(self.viz_dir, self.run_from_source, minimal_output=self.minimal_output)
        self._ensure_dir(self.data_dir)
        self._ensure_dir(self.current_dir)
        # NOTE: The database has a tendency to grow in size.
        # Old reports will have violations and metrics with references
        # to old packages, files, etc. There will be multiple versions
        # of the same projects over time, as long as the history exists.
        # This is why I added "_compact()" to the database's save_state()
        # function.
        if not self.minimal_output:
            self.database.save_state(os.path.join(self.current_dir, "haros.db"))
        self.log.debug("Exporting on-memory data manager.")
        self._prepare_project()
        exporter = JsonExporter()
        self._export_project_data(exporter)
        exporter.export_projects(self.data_dir, (self.database.project,),
                                 overwrite = False)

def _prepare_directory(self):
        if self.export_viz:
            viz.install(self.viz_dir, self.run_from_source)
        self._ensure_dir(self.data_dir)
        self._ensure_dir(self.io_projects_dir)