code: def test_toplevel_item(self):
      assert self.scatter["fillcolor"] is None
      self.scatter["fillcolor"] = "green"
      assert self.scatter["fillcolor"] == "green"
  
      d1, d2 = strip_dict_params(self.scatter, self.expected_toplevel)
      assert d1 == d2
  
imports: from unittest import TestCase
  import plotly.graph_objs
  from plotly.tests.utils import strip_dict_params
label_desc: Use image node_id 3 for calling the TestAssignmentPrimitive obj's underlying member method code with example usage: obj.test_toplevel_item() without return types