class_docstr: Iterable of DOT Source code lines
  (mimics ``file`` objects in text mode).
docstr: Yield the generated DOT source line by line.
  
  Yields: Line ending with a newline (``'\n'``).
code: def __iter__(self) -> typing.Iterator[str]:  # pragma: no cover
      r"""Yield the generated DOT source line by line.
  
      Yields: Line ending with a newline (``'\n'``).
      """
      raise NotImplementedError(
          "to be implemented by concrete subclasses"
      )
  
file_path: graphviz/graphviz/base.py
imports: import typing
  from .None import copying
label_desc: Use image node_id 1 for calling the LineIterable obj's underlying member method code with example usage: obj.__iter__() without return types