code: def test_check_malformed_graph_source_no_edge_start_or_end(
      self,
  ) -> None:
      edge_source = ColumnDataSource()
      edge_renderer = bmr.GlyphRenderer(
          data_source=edge_source, glyph=MultiLine()
      )
      renderer = bmr.GraphRenderer(edge_renderer=edge_renderer)
  
      check = renderer._check_malformed_graph_source()
      assert check != []
  
file_path: bokeh/tests/unit/bokeh/models/test_graph_renderer.py
imports: from __future__ import annotations
  import pytest
  from bokeh.models import Circle, ColumnDataSource, MultiLine, StaticLayoutProvider
  import bokeh.models.renderers
label_desc: Use image node_id 4 for calling the TestGraphRenderer obj's underlying member method code with example usage: obj.test_check_malformed_graph_source_no_edge_start_or_end() without return types