code: def get_institute_graph_url(start, end):
      
  
      filename = get_institute_graph_filename(start, end)
      urls = {
          'graph_url': urlparse.urljoin(GRAPH_URL, filename + ".png"),
          'data_url': urlparse.urljoin(GRAPH_URL, filename + ".csv"),
      }
  
      return urls
docs: Pie chart comparing institutes usage.