diff --git a/tutorials/Getting_Started.ipynb b/tutorials/Getting_Started.ipynb
old mode 100755
new mode 100644
index 195a3fea0b4a2dc1baceed6b184489e37770badf..032fbee2a75721b8449e137cdf7ea082842ef704
--- a/tutorials/Getting_Started.ipynb
+++ b/tutorials/Getting_Started.ipynb
@@ -340,84 +340,6 @@
       "execution_count": 0,
       "outputs": []
     },
-    {
-      "cell_type": "markdown",
-      "metadata": {
-        "id": "4BuCZavJKZNx",
-        "colab_type": "text"
-      },
-      "source": [
-        "`BiSession` allows two agents chat in dialog act level or natural language level, once the input and output are consistent. Example configurations: \n",
-        "\n",
-        "| user input ==> | user NLU | user DST | user Policy | user NLG | ==> sys input ==> | sys NLU | sys DST | sys Policy | sys NLG | \n",
-        "| ---------------- | ------- | ------- | ---------- | -------- | ---------------- | ------- | ------- | ---------- | -------- | \n",
-        "| Dialog act | None | Rule | Rule | None | Dialog act | None | None | Rule | None | \n",
-        "| Natural language | Bert | Rule | Rule | None | Dialog act | None | None | Rule | Template | \n",
-        "| Dialog act | None | Rule | Rule | Template | Natural language | MILU | None | Rule | None | \n",
-        "| Natural language | Bert | Rule | Rule | Template | Natural language | MILU | None | Rule | Template | \n",
-        "\n",
-        "We have tried the last configuration before. Let's try the second configuration."
-      ]
-    },
-    {
-      "cell_type": "code",
-      "metadata": {
-        "id": "vmdmODqt9goh",
-        "colab_type": "code",
-        "colab": {}
-      },
-      "source": [
-        "user_agent = PipelineAgent(user_nlu, user_dst, user_policy, None, name='user')\n",
-        "sys_agent = PipelineAgent(None, sys_dst, sys_policy, sys_nlg, name='sys')\n",
-        "evaluator = MultiWozEvaluator()\n",
-        "sess = BiSession(sys_agent=sys_agent, user_agent=user_agent, kb_query=None, evaluator=evaluator)"
-      ],
-      "execution_count": 0,
-      "outputs": []
-    },
-    {
-      "cell_type": "code",
-      "metadata": {
-        "id": "3o1B_hzzLjlm",
-        "colab_type": "code",
-        "colab": {}
-      },
-      "source": [
-        "set_seed(20200131)\n",
-        "\n",
-        "sys_response = ''\n",
-        "sess.init_session()\n",
-        "print('init goal:')\n",
-        "pprint(sess.evaluator.goal)\n",
-        "print('-'*50)\n",
-        "for i in range(20):\n",
-        "    sys_response, user_response, session_over, reward = sess.next_turn(sys_response)\n",
-        "    print('user:', user_response)\n",
-        "    print('sys:', sys_response)\n",
-        "    print()\n",
-        "    if session_over is True:\n",
-        "        break\n",
-        "print('task success:', sess.evaluator.task_success())\n",
-        "print('book rate:', sess.evaluator.book_rate())\n",
-        "print('inform precision/recall/f1:', sess.evaluator.inform_F1())\n",
-        "print('-'*50)\n",
-        "print('final goal:')\n",
-        "pprint(sess.evaluator.goal)\n",
-        "print('='*100)"
-      ],
-      "execution_count": 0,
-      "outputs": []
-    },
-    {
-      "cell_type": "markdown",
-      "metadata": {
-        "id": "LuE75fmULknS",
-        "colab_type": "text"
-      },
-      "source": [
-        "After removing user NLG and system NLU, the conversation is more efficient."
-      ]
-    },
     {
       "cell_type": "markdown",
       "metadata": {