fill array slow.scala

      val size = loop(0, 0)
      //put in the buffer
      val buf = ByteBuffer.allocate(size)
      node.zipWithIndex foreach {
        case (EmptyChild, _) => Unit

        case (Leaf(leafPrefix, value, varLength), idx) =>
          buf.put(idx.toByte) //first byte - number of children

          if (varLength) {
            //01000000b | (size & 00011111b)
            buf.put((0x40 | (leafPrefix.size & 0x1F)).toByte) //second byte - type and size of prefix
            buf.put(leafPrefix.toArray)                       //prefix sequence
            buf.put(value.size.toByte)                        //size of value
          } else {
            //size & 00011111b
            buf.put((leafPrefix.size & 0x1F).toByte) //second byte - type and size of prefix
            buf.put(leafPrefix.toArray)              //prefix sequence
          }
          buf.put(value.toArray) //value sequence

        case (NodePtr(ptrPrefix, ptr), idx) =>
          buf.put(idx.toByte) //first byte - number of children
          //10000000b | (size & 00011111b)
          buf.put((0x80 | (ptrPrefix.size & 0x1F)).toByte) //second byte - type and size of prefix
          buf.put(ptrPrefix.toArray)                       //prefix sequence
          buf.put(ptr.toArray)                             //size of value
      }
      buf.rewind
      val arr = new Array[Byte](buf.remaining())
      buf.get(arr)