code: def geojson(filename, color='b', linewidth=1, fill=False, f_tooltip=None):
      
      from geoplotlib.layers import GeoJSONLayer
      _global_config.layers.append(GeoJSONLayer(filename, color=color, linewidth=linewidth, fill=fill, f_tooltip=f_tooltip))
docs: Draw features described in geojson format (http://geojson.org/)
  
      :param filename: filename of the geojson file
      :param color: color for the shapes. If callable, it will be invoked for each feature, passing the properties element
      :param linewidth: line width
      :param fill: if fill=True the feature polygon is filled, otherwise just the border is rendered
      :param f_tooltip: function to generate a tooltip on mouseover. It will be invoked for each feature, passing the properties element