flex_source_code = "https://github.com/danielfrg/jupyter-flex/blob/master/examples/layouts/pages.ipynb"
"Page 1 - Col 1"
"Page 1 - Col 2 - Tab 1"
"Page 1 - Col 2 - Tab 2"
"Page 2 - Row 1 - Tab 1"
"Page 2 - Row 1 - Tab 2"
"Page 1 - Row 2"