code: def view(self, filename=None, directory=None, cleanup=False):
          
          return self.render(filename=filename, directory=directory, view=True,
                             cleanup=cleanup)
docs: Save the source to file, open the rendered result in a viewer.
  
          Args:
              filename: Filename for saving the source (defaults to ``name`` + ``'.gv'``)
              directory: (Sub)directory for source saving and rendering.
              cleanup (bool): Delete the source file after rendering.
          Returns:
              The (possibly relative) path of the rendered file.
          Raises:
              graphviz.ExecutableNotFound: If the Graphviz executable is not found.
              subprocess.CalledProcessError: If the exit status is non-zero.
              RuntimeError: If opening the viewer is not supported.
  
          Short-cut method for calling :meth:`.render` with ``view=True``.