src/vs/workbench/contrib/notebook/browser/viewParts/notebookEditorToolbar.ts/NotebookEditorToolbar/_canBeVisible
class NotebookEditorToolbar:	private _canBeVisible(width: number) {
		let w = 0;
		for (let i = 0; i < this._primaryActions.length; i++) {
			w += this._primaryActions[i].size + 8;
		}

		return w <= width;
	}