code: def test_heatmap_base(fake_writer):
      value = [
          [i, j, random.randint(0, 50)]
          for i in range(24)
          for j in range(7)
      ]
      c = (
          HeatMap()
          .add_xaxis(Faker.clock)
          .add_yaxis("series0", Faker.week, value)
          .set_global_opts(visualmap_opts=opts.VisualMapOpts())
      )
      c.render()
      _, content = fake_writer.call_args[0]
      assert_equal(c.theme, "white")
      assert_equal(c.renderer, "canvas")
  
imports: import random
  from unittest.mock import patch
  from nose.tools import assert_equal
  from pyecharts import options
  from pyecharts.charts import HeatMap
  from pyecharts.faker import Faker
label_desc: Use image node_id 1 for calling a global function with example usage: test_heatmap_base(fake_writer) without return types