class_docstr: Verbatim DOT source code string to be rendered by Graphviz.
  
  Args:
      source: The verbatim DOT source code string.
      filename: Filename for saving the source (defaults to ``'Source.gv'``).
      directory: (Sub)directory for source saving and rendering.
      format: Rendering output format (``'pdf'``, ``'png'``, ...).
      engine: Layout engine used (``'dot'``, ``'neato'``, ...).
      encoding: Encoding for saving the source.
  
  Note:
      All parameters except ``source`` are optional. All of them
      can be changed under their corresponding attribute name
      after instance creation.
docstr: Yield the DOT source code read from file line by line.
  
  Yields: Line ending with a newline (``'\n'``).
docstr_tok: ["Yield","the","DOT","source","code","read","from","file","line","by","line",".","Yields",":","Line","ending","with","a","newline","(","``","'\\n","'","``",")","."]
code: def __iter__(self) -> typing.Iterator[str]:
      r"""Yield the DOT source code read from file line by line.
  
      Yields: Line ending with a newline (``'\n'``).
      """
      lines = self._source.splitlines(keepends=True)
      yield from lines[:-1]
      for line in lines[-1:]:
          suffix = "\n" if not line.endswith("\n") else ""
          yield line + suffix
  
imports: import locale
  import logging
  import os
  import typing
  from .encoding import DEFAULT_ENCODING
  from .None import _tools
  from .None import saving
  from .None import jupyter_integration
  from .None import piping
  from .None import rendering
  from .None import unflattening
label_desc: Use image node_id 4 for calling the Source obj's underlying member method code with example usage: obj.__iter__() without return types