(defn eager-tree-seq [branch? children root]
  < 1 >
            (let [res (conj! res root)]
              (if (branch? root)
                (reduce step res (children root))
                res)))]
  < 2 >
(defn eager-tree-seq [branch? children root]
  < 1 >
            (let [res (conj! res root)]
              (if (branch? root)
                (reduce step res (children root))
                res)))]
  < 2 >