code: def voronoi(data, line_color=None, line_width=2, f_tooltip=None, cmap=None, max_area=1e4, alpha=220):
      
      from geoplotlib.layers import VoronoiLayer
      _global_config.layers.append(VoronoiLayer(data, line_color, line_width, f_tooltip, cmap, max_area, alpha))
docs: Draw the voronoi tesselation of the points
  
      :param data: data access object
      :param line_color: line color
      :param line_width: line width
      :param f_tooltip: function to generate a tooltip on mouseover
      :param cmap: color map
      :param max_area: scaling constant to determine the color of the voronoi areas
      :param alpha: color alpha