voronoi.extent()

voronoi.extent([extent])

If extent is specified, sets the clip extent of the Voronoi layout to the specified bounds and returns the layout. The extent bounds are specified as an array [[x0, y0], [x1, y1]], where x0 is the left side of the extent, y0 is the top, x1 is the right and y1 is the bottom. If extent is not specified, returns the current clip extent which defaults to null. A clip extent is required when using voronoi.polygons.