class_docstr: Rendering engine parameter with ``'dot''`` default.
code: def engine(self, engine: str) -> None:
      engine = engine.lower()
      self._verify_engine(engine)
      self._engine = engine
  
file_path: graphviz/graphviz/parameters/engines.py
imports: import typing
  from .None import base
label_desc: Use image node_id 4 for calling the Engine obj's underlying member method code with example usage: obj.engine(engine) without return types