code: def test_label_options_defaults():
      option = LabelOpts()
      expected = {
          "show": True,
          "position": None,
          "color": None,
          "distance": None,
          "rotate": None,
          "margin": 8,
          "interval": None,
          "fontSize": None,
          "fontStyle": None,
          "fontWeight": None,
          "fontFamily": None,
          "align": None,
          "verticalAlign": None,
          "formatter": None,
          "backgroundColor": None,
          "borderColor": None,
          "borderWidth": None,
          "borderRadius": None,
          "rich": None,
      }
      assert_equal(expected, option.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 1 for calling a global function with example usage: test_label_options_defaults() without return types