docs: function dumpHistory(history, size, depth) {
      console.log("Hash table history, size="+size+", average depth="+depth);
      for (var n=0; n < history.length; n++) {
          console.log("  Depth=" + n + ", count=" + history[n] + ", percent=" + (history[n] / size));
      }
      console.log("");
  }