clear the example notebook

Author: Dou Du

example/example.ipynb

@@ -2,7 +2,7 @@
  "cells": [
   {
    "cell_type": "code",
-   "execution_count": 78,
+   "execution_count": null,
    "id": "5df2c405",
    "metadata": {},
    "outputs": [],
@@ -25,33 +25,17 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 79,
+   "execution_count": null,
    "id": "e74c9c9e",
    "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "application/vnd.jupyter.widget-view+json": {
-       "model_id": "f0db00d571a747f2ae74b66557f21acd",
-       "version_major": 2,
-       "version_minor": 1
-      },
-      "text/plain": [
-       "CodeInputWidget(code_theme='basicLight', docstring='\\n   Input docstring here.\\n', function_body='# Give infor…"
-      ]
-     },
-     "execution_count": 79,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
+   "outputs": [],
    "source": [
     "w"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 80,
+   "execution_count": null,
    "id": "4d389a14",
    "metadata": {},
    "outputs": [],
@@ -61,28 +45,17 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 81,
+   "execution_count": null,
    "id": "2fc2b3ed",
    "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "text/plain": [
-       "3"
-      ]
-     },
-     "execution_count": 81,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
+   "outputs": [],
    "source": [
     "my_function(1, 2)"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 82,
+   "execution_count": null,
    "id": "601edb7d",
    "metadata": {},
    "outputs": [],
@@ -92,7 +65,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 83,
+   "execution_count": null,
    "id": "e90010bd",
    "metadata": {},
    "outputs": [],
@@ -102,26 +75,10 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 84,
+   "execution_count": null,
    "id": "75900629",
    "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "application/vnd.jupyter.widget-view+json": {
-       "model_id": "81302242542b4e30a4cfc301389f6278",
-       "version_major": 2,
-       "version_minor": 1
-      },
-      "text/plain": [
-       "CodeInputWidget(code_theme='basicLight', docstring='\\n   Input docstring here.\\n', function_body='# Give infor…"
-      ]
-     },
-     "execution_count": 84,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
+   "outputs": [],
    "source": [
     "w2 = CodeInputWidget(\n",
     "   function_name = \"my_function\",\n",