def get_records(ShardIterator=None, Limit=None):
    """
    Gets data records from an Amazon Kinesis stream's shard.
    Specify a shard iterator using the ShardIterator parameter. The shard iterator specifies the position in the shard from which you want to start reading data records sequentially. If there are no records available in the portion of the shard that the iterator points to,  GetRecords returns an empty list. Note that it might take multiple calls to get to a portion of the shard that contains records.
    You can scale by provisioning multiple shards per stream while considering service limits (for more information, see Streams Limits in the Amazon Kinesis Streams Developer Guide ). Your application should have one thread per shard, each reading continuously from its stream. To read from a stream continually, call  GetRecords in a loop. Use  GetShardIterator to get the shard iterator to specify in the first  GetRecords call.  GetRecords returns a new shard iterator in NextShardIterator . Specify the shard iterator returned in NextShardIterator in subsequent calls to  GetRecords . Note that if the shard has been closed, the shard iterator can't return more data and  GetRecords returns null in NextShardIterator . You can terminate the loop when the shard is closed, or when the shard iterator reaches the record with the sequence number or other attribute that marks it as the last record to process.
    Each data record can be up to 1 MB in size, and each shard can read up to 2 MB per second. You can ensure that your calls don't exceed the maximum supported size or throughput by using the Limit parameter to specify the maximum number of records that  GetRecords can return. Consider your average record size when determining this limit.
    The size of the data returned by  GetRecords varies depending on the utilization of the shard. The maximum size of data that  GetRecords can return is 10 MB. If a call returns this amount of data, subsequent calls made within the next 5 seconds throw ProvisionedThroughputExceededException . If there is insufficient provisioned throughput on the shard, subsequent calls made within the next 1 second throw ProvisionedThroughputExceededException . Note that  GetRecords won't return any data when it throws an exception. For this reason, we recommend that you wait one second between calls to  GetRecords ; however, it's possible that the application will get exceptions for longer than 1 second.
    To detect whether the application is falling behind in processing, you can use the MillisBehindLatest response attribute. You can also monitor the stream using CloudWatch metrics and other mechanisms (see Monitoring in the Amazon Kinesis Streams Developer Guide ).
    Each Amazon Kinesis record includes a value, ApproximateArrivalTimestamp , that is set when a stream successfully receives and stores a record. This is commonly referred to as a server-side timestamp, whereas a client-side timestamp is set when a data producer creates or sends the record to a stream (a data producer is any data source putting data records into a stream, for example with  PutRecords ). The timestamp has millisecond precision. There are no guarantees about the timestamp accuracy, or that the timestamp is always increasing. For example, records in a shard or across a stream might have timestamps that are out of order.
    See also: AWS API Documentation
    
    
    :example: response = client.get_records(
        ShardIterator='string',
        Limit=123
    )
    
    
    :type ShardIterator: string
    :param ShardIterator: [REQUIRED]
            The position in the shard from which you want to start sequentially reading data records. A shard iterator specifies this position using the sequence number of a data record in the shard.
            

    :type Limit: integer
    :param Limit: The maximum number of records to return. Specify a value of up to 10,000. If you specify a value that is greater than 10,000, GetRecords throws InvalidArgumentException .

    :rtype: dict
    :return: {
        'Records': [
            {
                'SequenceNumber': 'string',
                'ApproximateArrivalTimestamp': datetime(2015, 1, 1),
                'Data': b'bytes',
                'PartitionKey': 'string'
            },
        ],
        'NextShardIterator': 'string',
        'MillisBehindLatest': 123
    }
    
    
    """
    pass
