src/vs/workbench/contrib/notebook/browser/notebookEditorWidget.ts/NotebookEditorWidget/didStartDragMarkupCell
class NotebookEditorWidget:	didStartDragMarkupCell(cellId: string, event: { dragOffsetY: number; }): void {
		const cell = this.getCellById(cellId);
		if (cell instanceof MarkupCellViewModel) {
			this._dndController?.startExplicitDrag(cell, event.dragOffsetY);
		}
	}