Hiding code cell on launch

JupyterLab
10

@arouneaj, below is what the json source for my cell looks like, and JupyterLab (v 1.0.2) displays it hidden when the notebook is loaded. Maybe you’re setting the metatag in the wrong place?

{
   "cell_type": "code",
   "execution_count": 53,
   "metadata": {
       "jupyter": {
           "source_hidden": true
        }
},
"outputs": []...