class_docstr: Test ability to marshall graphviz_chart protos.
docstr: Test that it can be called with spec.
docstr_tok: ["Test","that","it","can","be","called","with","spec","."]
code: def test_spec(self):
      """Test that it can be called with spec."""
      graph = graphviz.Graph(comment="The Round Table")
      graph.node("A", "King Arthur")
      graph.node("B", "Sir Bedevere the Wise")
      graph.edges(["AB"])
  
      st.graphviz_chart(graph)
  
      c = self.get_delta_from_queue().new_element.graphviz_chart
      self.assertEqual(hasattr(c, "spec"), True)
  
file_path: streamlit/lib/tests/streamlit/elements/graphviz_test.py
imports: import graphviz
  import streamlit
  from tests.delta_generator_test_case import DeltaGeneratorTestCase
label_desc: Use image node_id 1 for calling the GraphvizTest obj's underlying member method code with example usage: obj.test_spec() without return types