def handle(self, *args, **options):
        """Register processes."""
        force = options.get('force')
        retire = options.get('retire')
        verbosity = int(options.get('verbosity'))

        users = get_user_model().objects.filter(is_superuser=True).order_by('date_joined')

        if not users.exists():
            self.stderr.write("Admin does not exist: create a superuser")
            exit(1)

        process_paths, descriptor_paths = [], []
        process_schemas, descriptor_schemas = [], []

        for finder in get_finders():
            process_paths.extend(finder.find_processes())
            descriptor_paths.extend(finder.find_descriptors())

        for proc_path in process_paths:
            process_schemas.extend(
                self.find_schemas(proc_path, schema_type=SCHEMA_TYPE_PROCESS, verbosity=verbosity))

        for desc_path in descriptor_paths:
            descriptor_schemas.extend(
                self.find_schemas(desc_path, schema_type=SCHEMA_TYPE_DESCRIPTOR, verbosity=verbosity))

        user_admin = users.first()
        self.register_descriptors(descriptor_schemas, user_admin, force, verbosity=verbosity)
        # NOTE: Descriptor schemas must be registered first, so
        #       processes can validate 'entity_descriptor_schema' field.
        self.register_processes(process_schemas, user_admin, force, verbosity=verbosity)

        if retire:
            self.retire(process_schemas)

        if verbosity > 0:
            self.stdout.write("Running executor post-registration hook...")
        manager.get_executor().post_register_hook(verbosity=verbosity)
Register processes.