Add static files view.

        prefix - url prefix
        path - folder with files

def add_static(self, prefix: str, path: PathLike, *,
                   name: Optional[str]=None,
                   expect_handler: Optional[_ExpectHandler]=None,
                   chunk_size: int=256 * 1024,
                   show_index: bool=False, follow_symlinks: bool=False,
                   append_version: bool=False) -> AbstractResource:
        """Add static files view.

        prefix - url prefix
        path - folder with files

        """
        assert prefix.startswith('/')
        if prefix.endswith('/'):
            prefix = prefix[:-1]
        resource = StaticResource(prefix, path,
                                  name=name,
                                  expect_handler=expect_handler,
                                  chunk_size=chunk_size,
                                  show_index=show_index,
                                  follow_symlinks=follow_symlinks,
                                  append_version=append_version)
        self.register_resource(resource)
        return resource