code: def test_mark_point_item_remove_none():
      item = MarkPointItem()
      expected = {}
      assert_equal(expected, remove_key_with_none_value(item.opts))
  
file_path: pyecharts/test/test_series_options.py
imports: from nose.tools import assert_equal
  from pyecharts.commons.utils import remove_key_with_none_value
  from pyecharts.options.series_options import LabelOpts, ItemStyleOpts, MarkPointItem, MarkLineItem, MarkAreaItem, MarkAreaOpts, MinorTickOpts, MinorSplitLineOpts, TreeMapBreadcrumbOpts
label_desc: Use image node_id 3 for calling a global function with example usage: test_mark_point_item_remove_none() without return types