code: def add_synonym(
      synonym_value: Text,
      synonym_name: Text,
      existing_synonyms: Dict[Text, Any],
  ) -> None:
      """Adds a new synonym mapping to the provided list of synonyms.
  
      Args:
          synonym_value: Value of the synonym.
          synonym_name: Name of the synonym.
          existing_synonyms: Dictionary will synonym mappings that will be extended.
      """
      import rasa.shared.nlu.training_data.util as training_data_util
  
      training_data_util.check_duplicate_synonym(
          existing_synonyms,
          synonym_value,
          synonym_name,
          "reading markdown",
      )
      existing_synonyms[synonym_value] = synonym_name
  
label_desc: Use image node_id 2 for calling a global function with example usage: add_synonym(synonym_value, synonym_name, existing_synonyms) without return types