Finish state saving

example/test.ipynb

@@ -2,6 +2,7 @@
  "cells": [
   {
    "cell_type": "code",
+   "execution_count": null,
    "metadata": {
     "tags": []
    },
@@ -53,6 +54,7 @@
   },
   {
    "cell_type": "code",
+   "execution_count": null,
    "metadata": {
     "tags": []
    },
@@ -76,6 +78,7 @@
   },
   {
    "cell_type": "code",
+   "execution_count": null,
    "metadata": {
     "tags": []
    },
@@ -87,6 +90,7 @@
        "<IPython.core.display.Image object>"
       ]
      },
+     "execution_count": null,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -98,6 +102,7 @@
   },
   {
    "cell_type": "code",
+   "execution_count": null,
    "metadata": {
     "tags": []
    },

src/notebook/cells/model.ts

@@ -402,6 +402,7 @@ namespace Private {
   export
   const executionCountProperty = new Property<CodeCellModel, number>({
     name: 'executionCount',
+    value: null,
     notify: stateChangedSignal,
   });
 }

src/notebook/notebook/serialize.ts

@@ -144,6 +144,7 @@ function saveNotebook(nb: NotebookModel, contents: IContentsManager): Promise<IC
   let cells = getNotebookData(nb);
   return nb.session.kernel.kernelInfo().then(info => {
     let name = nb.session.kernel.name;
+    // TODO: Get the display name.
     let metadata = { kernelspec: { name, display_name: name },
                      language_info: info.language_info
                    };