code: def __init__(self):
      super().__init__(
          "set-default-viewer", "Set default viewers for JupyterLab"
      )
  
imports: import sys
  from argparse import ArgumentParser
  from pathlib import Path
  import jupyter_core.paths
  from .labconfig import LabConfig
label_desc: Use image node_id 1 to create a new SetDefaultViewer object from inherited base classes: SubCommand with example: obj = SetDefaultViewer()