code: def to_json(self):
      # used in serializing wildcards - arrays are not allowed as
      # id values, so make the wildcards look like length-1 arrays.
      return f'["{self._name}"]'
  
imports: import json
  from dash.development.base_component import Component
  from ._validate import validate_callback
  from ._grouping import flatten_grouping, make_grouping_by_index
label_desc: Use image node_id 4 for calling the _Wildcard obj's underlying member method code with example usage: obj.to_json() and returns: str, self, str