Function b

Returns {
    ac: null;
    b: any;
    ctx: any;
    deps: null;
    f: number;
    first: null;
    fn: any;
    last: null;
    next: null;
    nodes_end: null;
    nodes_start: null;
    parent: any;
    prev: null;
    teardown: null;
    transitions: null;
    wv: number;
}