class_docstr: SnsPayload class
docstr: Pre-parsing method for SNS records
  
  Extracts the SNS message payload from the record.
  
  Yields:
      Instances of PayloadRecord back to the caller containing the current log data
docstr_tok: ["Pre-parsing","method","for","SNS","records","Extracts","the","SNS","message","payload","from","the","record",".","Yields",":","Instances","of","PayloadRecord","back","to","the","caller","containing","the","current","log","data"]
code: def _pre_parse(self):
      """Pre-parsing method for SNS records
  
      Extracts the SNS message payload from the record.
  
      Yields:
          Instances of PayloadRecord back to the caller containing the current log data
      """
      LOGGER.debug(
          "Pre-parsing record from SNS. MessageId: %s, EventSubscriptionArn: %s",
          self.raw_record["Sns"]["MessageId"],
          self.raw_record["EventSubscriptionArn"],
      )
  
      yield PayloadRecord(self.raw_record["Sns"]["Message"])
  
imports: import logging
  from streamalert.classifier.payload.payload_base import PayloadRecord, RegisterInput, StreamPayload
  from streamalert.shared.logger import get_logger
label_desc: Use image node_id 2 for calling the SnsPayload obj's underlying member method code with example usage: obj._pre_parse() without return types