diff --git a/IPython/nbformat/v4/v4.withref.json b/IPython/nbformat/v4/v4.withref.json
index 6da87ea..d775162 100644
--- a/IPython/nbformat/v4/v4.withref.json
+++ b/IPython/nbformat/v4/v4.withref.json
@@ -1,100 +1,100 @@
 {
     "description": "custom json structure with references to generate notebook schema",
     "notebook":{
-      "type": "object",
-      "description": "notebook v4.0 root schema",
-      "$schema": "http://json-schema.org/draft-03/schema",
-      "id": "#notebook",
-      "required": true,
-      "additionalProperties": false,
-      "properties":{
-        "metadata": {
-          "type": "object",
-          "id": "metadata",
-          "required": true,
-          "description": "the metadata atribute can contain any additionnal information",
-          "additionalProperties": true,
-          "properties":{
-            "name": {
-              "id": "name",
-              "description": "the title of the notebook",
-              "type": "string",
-              "id": "name",
-              "required": true
+        "type": "object",
+        "description": "notebook v4.0 root schema",
+        "$schema": "http://json-schema.org/draft-03/schema",
+        "id": "#notebook",
+        "required": true,
+        "additionalProperties": false,
+        "properties":{
+            "metadata": {
+                "type": "object",
+                "id": "metadata",
+                "required": true,
+                "description": "the metadata atribute can contain any additionnal information",
+                "additionalProperties": true,
+                "properties":{
+                    "name": {
+                        "id": "name",
+                        "description": "the title of the notebook",
+                        "type": "string",
+                        "id": "name",
+                        "required": true
+                    }
+                }
+            },
+            "nbformat_minor": {
+                "description": "Notebook format, minor number. Incremented for slight variation of notebook format.",
+                "type": "integer",
+                "minimum": 0,
+                "id": "nbformat_minor",
+                "required": true
+            },
+            "nbformat": {
+                "description": "Notebook format, major number. Incremented between backward incompatible change is introduced.",
+                "type": "integer",
+                "minimum": 4,
+                "id": "nbformat",
+                "required": true
+            },
+            "orig_nbformat": {
+                "description": "Original notebook format, major number.",
+                "type": "integer",
+                "minimum": 1,
+                "id": "orig_nbformat",
+                "required": false
+            },
+            "cells": {
+                "$schema": "http://json-schema.org/draft-03/schema",
+                "description": "array of cells of the current worksheet",
+                "type": "array",
+                "id": "#cells",
+                "required": true,
+                "items": {"$ref": "/any_cell"}
             }
-          }
-        },
-        "nbformat_minor": {
-          "description": "Notebook format, minor number. Incremented for slight variation of notebook format.",
-          "type": "integer",
-          "minimum": 0,
-          "id": "nbformat_minor",
-          "required": true
-        },
-        "nbformat": {
-          "description": "Notebook format, major number. Incremented between backward incompatible change is introduced.",
-          "type": "integer",
-          "minimum": 4,
-          "id": "nbformat",
-          "required": true
-        },
-        "orig_nbformat": {
-          "description": "Original notebook format, major number.",
-          "type": "integer",
-          "minimum": 1,
-          "id": "orig_nbformat",
-          "required": false
-        },
-        "cells": {
-          "$schema": "http://json-schema.org/draft-03/schema",
-          "description": "array of cells of the current worksheet",
-          "type": "array",
-          "id": "#cells",
-          "required": true,
-          "items": {"$ref": "/any_cell"}
         }
-      }
     },
 
     "text_cell": {
-      "type": "object",
-      "description": "scheme for text cel and childrenm (level only optionnal argument for HEader cell)",
-      "$schema": "http://json-schema.org/draft-03/schema",
-      "id": "#cell",
-      "required": true,
-      "additionalProperties": false,
-      "properties":{
-        "cell_type": {
-          "type": "string",
-          "id": "cell_type",
-          "required": true
-        },
-        "level": {
-          "type": "integer",
-          "minimum": 1,
-          "maximum": 6,
-          "id": "level",
-          "required": false
-        },
-        "metadata": {
-          "type": "object",
-          "id": "metadata",
-          "required": false
-        },
-        "source": {
-          "description": "for code cell, the source code",
-          "type": ["array", "string"],
-          "id": "source",
-          "required": true,
-          "items":
-            {
-              "type": "string",
-              "description": "each item represent one line of the source code written, terminated by \n",
-              "id": "0",
-              "required": true
+        "type": "object",
+        "description": "scheme for text cel and childrenm (level only optionnal argument for HEader cell)",
+        "$schema": "http://json-schema.org/draft-03/schema",
+        "id": "#cell",
+        "required": true,
+        "additionalProperties": false,
+        "properties":{
+            "cell_type": {
+                "type": "string",
+                "id": "cell_type",
+                "required": true
+            },
+            "level": {
+                "type": "integer",
+                "minimum": 1,
+                "maximum": 6,
+                "id": "level",
+                "required": false
+            },
+            "metadata": {
+                "type": "object",
+                "id": "metadata",
+                "required": false
+            },
+            "source": {
+                "description": "for code cell, the source code",
+                "type": ["array", "string"],
+                "id": "source",
+                "required": true,
+                "items":
+                {
+                    "type": "string",
+                    "description": "each item represent one line of the source code written, terminated by \n",
+                    "id": "0",
+                    "required": true
+                }
             }
         }
-      }
 
     },
 
@@ -105,54 +105,53 @@
     },
 
     "code_cell":{
-      "type": "object",
-      "$schema": "http://json-schema.org/draft-03/schema",
-      "description": "Cell used to execute code",
-      "id": "#cell",
-      "required": true,
-      "additionalProperties": false,
-      "properties":{
-        "cell_type": {
-          "type": "string",
-          "id": "cell_type",
-          "required": true
-        },
-        "metadata": {
-          "type": "object",
-          "id": "metadata",
-          "required": false
-        },
-        "collapsed": {
-          "type": "boolean",
-          "required": true
-        },
-        "input": {
-          "description": "user input for text cells",
-          "type": ["array", "string"],
-          "id": "input",
-          "required": true,
-          "items":
-            {
-              "type": "string",
-              "id": "input",
-              "required": true
+        "type": "object",
+        "$schema": "http://json-schema.org/draft-03/schema",
+        "description": "Cell used to execute code",
+        "id": "#cell",
+        "required": true,
+        "additionalProperties": false,
+        "properties":{
+            "cell_type": {
+                "type": "string",
+                "id": "cell_type",
+                "required": true
+            },
+            "metadata": {
+                "type": "object",
+                "id": "metadata",
+                "required": false
+            },
+            "collapsed": {
+                "type": "boolean",
+                "required": true
+            },
+            "input": {
+                "description": "user input for text cells",
+                "type": ["array", "string"],
+                "id": "input",
+                "required": true,
+                "items":
+                {
+                    "type": "string",
+                    "id": "input",
+                    "required": true
+                }
+            },
+            "outputs": {
+                "description": "output for code cell, to be definied",
+                "required": true,
+                "type": "array"
+            },
+            "prompt_number": {
+                "type": ["integer","null"],
+                "required": false,
+                "minimum": 0
+            },
+            "language": {
+                "type": "string",
+                "required": true
             }
-        },
-        "outputs": {
-            "description": "output for code cell, to be definied",
-            "required": true,
-            "type": "array"
-        },
-        "prompt_number": {
-            "type": ["integer","null"],
-            "required": false,
-            "minimum": 0
-        },
-        "language": {
-            "type": "string",
-            "required": true
         }
-      }
-
     }
 }