val: "0"
child_nodes {
  val: "010"
  child_nodes {
    val: "01020"
    child_nodes {
      val: "0102030"
    }
    child_nodes {
      val: "0102031"
    }
    child_nodes {
      val: "0102032"
    }
  }
  child_nodes {
    val: "01021"
    child_nodes {
      val: "0102130"
    }
    child_nodes {
      val: "0102131"
    }
    child_nodes {
      val: "0102132"
    }
  }
}