docstr: Method called before executing each block.
docstr_tok: ["Method","called","before","executing","each","block","."]
code: def pre_cmd(self):
      """Method called before executing each block."""
      pass
  
imports: import os
  import re
  import shlex
  import sys
  import pygments
  from pathlib import Path
  from IPython.utils.text import marquee
  from IPython.utils import openpy
  from IPython.utils import py3compat
label_desc: Use image node_id 17 for calling the Demo obj's underlying member method code with example usage: obj.pre_cmd() without return types