code: def default_engine(self):
      return self._default_engine
  
imports: import json
  import decimal
  import datetime
  import warnings
  from pathlib import Path
  from plotly.io._utils import validate_coerce_fig_to_dict, validate_coerce_output_type
  from _plotly_utils.optional_imports import get_module
  from _plotly_utils.basevalidators import ImageUriValidator
label_desc: Use image node_id 2 for calling the JsonConfig obj's underlying member method code with example usage: obj.default_engine() and returns: self