code: def test_pie_dataset(fake_writer):
      c = (
          Pie()
          .add_dataset(
              source=[
                  [
                      "product",
                      "2012",
                      "2013",
                      "2014",
                      "2015",
                      "2016",
                      "2017",
                  ],
                  ["Matcha Latte", 41.1, 30.4, 65.1, 53.3, 83.8, 98.7],
                  ["Milk Tea", 86.5, 92.1, 85.7, 83.1, 73.4, 55.1],
                  ["Cheese Cocoa", 24.1, 67.2, 79.5, 86.4, 65.2, 82.5],
                  [
                      "Walnut Brownie",
                      55.2,
                      67.1,
                      69.2,
                      72.4,
                      53.9,
                      39.1,
                  ],
              ]
          )
          .add(
              series_name="Matcha Latte",
              data_pair=[],
              radius=60,
              center=["25%", "30%"],
              encode={"itemName": "product", "value": "2012"},
          )
          .add(
              series_name="Milk Tea",
              data_pair=[],
              radius=60,
              center=["75%", "30%"],
              encode={"itemName": "product", "value": "2013"},
          )
          .add(
              series_name="Cheese Cocoa",
              data_pair=[],
              radius=60,
              center=["25%", "75%"],
              encode={"itemName": "product", "value": "2014"},
          )
          .add(
              series_name="Walnut Brownie",
              data_pair=[],
              radius=60,
              center=["75%", "75%"],
              encode={"itemName": "product", "value": "2015"},
          )
          .set_global_opts(
              title_opts=opts.TitleOpts(
                  title="Dataset simple pie example"
              ),
              legend_opts=opts.LegendOpts(pos_left="30%", pos_top="2%"),
          )
      )
      c.render()
      _, content = fake_writer.call_args[0]
      assert_equal(c.theme, "white")
      assert_equal(c.renderer, "canvas")
      assert_in("dataset", content)
  
imports: from unittest.mock import patch
  from nose.tools import assert_equal, assert_in
  from pyecharts import options
  from pyecharts.charts import Pie
  from pyecharts.faker import Faker
label_desc: Use image node_id 3 for calling a global function with example usage: test_pie_dataset(fake_writer) without return types