code: def dot(data, color=None, point_size=2, f_tooltip=None):
      """Create a dot density map
  
      :param data: data access object
      :param color: color
      :param point_size: point size
      :param f_tooltip: function to return a tooltip string for a point
      """
      from geoplotlib.layers import DotDensityLayer
  
      _global_config.layers.append(
          DotDensityLayer(
              data,
              color=color,
              point_size=point_size,
              f_tooltip=f_tooltip,
          )
      )
  
imports: import base64
  import traceback
  import pyglet
  from geoplotlib.core import GeoplotlibApp
  from core import FONT_NAME
label_desc: Use image node_id 5 for calling a global function with example usage: dot(data, color, point_size, f_tooltip) without return types