Update notebook

examples/notebook/linear_solver/mip_var_array.ipynb

@@ -27,6 +27,7 @@
     "# [END import]\n",
     "\n",
     "\n",
+    "# [START program_part1]\n",
     "# [START data_model]\n",
     "def create_data_model():\n",
     "    \"\"\"Stores the data for the problem.\"\"\"\n",
@@ -50,13 +51,14 @@
     "# [START data]\n",
     "data = create_data_model()\n",
     "# [END data]\n",
-    "\n",
+    "# [END program_part1]\n",
     "# [START solver]\n",
     "# Create the mip solver with the CBC backend.\n",
     "solver = pywraplp.Solver('simple_mip_program',\n",
     "                         pywraplp.Solver.CBC_MIXED_INTEGER_PROGRAMMING)\n",
     "# [END solver]\n",
     "\n",
+    "# [START program_part2]\n",
     "# [START variables]\n",
     "infinity = solver.infinity()\n",
     "x = {}\n",