code: function getSourceStreamNames(records, context) {
    const getSourceStreamName = isDynamoDBStreamType(context) ?
      record => {
        const [tableName, streamTimestamp] = streamEvents.getDynamoDBEventSourceTableNameAndStreamTimestamp(record);
        return tableName && streamTimestamp ? `${tableName}/${streamTimestamp}` : '';
      } : streamEvents.getKinesisEventSourceStreamName;
  
    return records.map(getSourceStreamName);
  }
docs: Extracts the source stream names from the given Kinesis or DynamoDB stream event records.
  For Kinesis: Extract the stream name from each of the records' eventSourceARNs
  For DynamoDB: Extract the table name and stream timestamp from each of the records' eventSourceARNs and join them with a '/'
  @param {AnyStreamEventRecord[]} records - the records from which to extract
  @param {StreamProcessing} context - the context from which to fetch the function
  @return {string[]} the source stream names