class_docstr: A collection of enum values.
  
  This collection can be used as specification to traitlets.Enum
  as it supports the `in` operator, and also supports tab completion
  as the values are attributes.
class_docstr_tok: ["A","collection","of","enum","values",".","This","collection","can","be","used","as","specification","to","traitlets.Enum","as","it","supports","the","`","in","`","operator",",","and","also","supports","tab","completion","as","the","values","are","attributes","."]
code: def __contains__(self, key):
      return key in self.__dict__
  
label_desc: Use image node_id 2 for calling the EnumNamespace obj's underlying member method code with example usage: obj.__contains__(key) and returns: unknown