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