code: def json_to_string(value, null_string_repr='[]', trimable=False):
      
      return null_string_repr if is_undefined(value) \
          else obj.jsonify(value, trimable=trimable)
docs: Return a string representation of the specified JSON object.
  
      @param value: a JSON object.
  
      @param null_string_rep: the string representation of the null
          object.
  
      @return: a string representation of the specified JSON object.