Sliders in notebook are unlinked from their plot if a new cell with sliders is executed
Noticed this with @fages mail yesterday when executing a notebook, when creating sliders in several cells, only the ones in the last cell executed works. The parameter value gets updated normally using the sliders, however the plot doesn't get rerendered. This is mostly due to ipywidgets sliders observe handler being deleted and not being linked to the plot anymore somehow.
cc @soliman