docs: public static Node allocMap() {
          Data.Map m = new Data.Map();
          m.style = MapStyle.None;
          m.idx = 0;
          m.capa = YAML.ALLOC_CT;
          m.keys = new Object[m.capa];
          m.values = new Object[m.capa];
          
          Node n = KindTag.Map.allocNode();
          n.data = m;
          return n;
      }