I have a setup where there is a node.js application that writes to a kinesis stream using putRecords for two items. The kinesis stream feeds a Lambda function that is configured with an eventSourceMapping with a batch size of 1. However, when I debug what the Records Kinesis feeds the lambda for an invocation, I see that the lambda is processing two records. Both of these records are on the same shard and have a sequence number which is pretty close.

The interesting thing is that if I switch the node.js published to use putRecord instead of putRecords, the kinesis records have a slightly farther apart sequence number and the lambda is fed the records individually.

The java code to configure the event source mapping
```
        AWSLambdaAsync lambdaClient = AWSResourceFactory.getLambdaClient();
        CreateEventSourceMappingRequest request = new CreateEventSourceMappingRequest();
        request.setEventSourceArn(kinesisArn);
        request.setFunctionName(functionName);
        request.setEnabled(true);
        request.setStartingPosition(EventSourcePosition.TRIM_HORIZON);
        request.setBatchSize(1);
        lambdaClient.createEventSourceMapping(request);
```

The localstack lambda output that shows multiple records being read at a time:

```
{
	"Records": [{
		"eventID": "shardId-000000000000:49593014281924840790139112603493819506073986345293840386",
		"eventSourceARN": "arn:aws:kinesis:us-east-1:000000000000:stream/MyStream",
		"kinesis": {
			"partitionKey": "ed0f756b97234f4fae9e3d1a886b8fbc",
			"data": "myData1",
			"sequenceNumber": "49593014281924840790139112603493819506073986345293840386"
		}
	}, {
		"eventID": "shardId-000000000000:49593014281924840790139112603495028431893600974468546562",
		"eventSourceARN": "arn:aws:kinesis:us-east-1:000000000000:stream/MyStream",
		"kinesis": {
			"partitionKey": "abee63a9299385699d65e89a290a9065",
			"data": "myData2",
			"sequenceNumber": "49593014281924840790139112603495028431893600974468546562"
		}
	}]
}
```

400, error_type='ValidationError'))
        if runtime.startswith('python') and not use_docker():
            try:
                
                ensure_readable(main_file)
                zip_file_content = load_file(main_file, mode='rb')
                
                lambda_handler = exec_lambda_code(
                    zip_file_content,
                    handler_function=handler_function,
                    lambda_cwd=lambda_cwd,
                    lambda_env=lambda_environment)
            except Exception as e:
                raise ClientError('Unable to get handler function from lambda code.', e)
    add_function_mapping(lambda_name, lambda_handler, lambda_cwd)
    return {'FunctionName': lambda_name}
def do_list_functions():
    funcs = []
    for f_arn, func in arn_to_lambda.items():
        if type(func) != LambdaFunction:
            continue
        func_name = f_arn.split(':function:')[-1]
        arn = func_arn(func_name)
        func_details = arn_to_lambda.get(arn)
        if not func_details:
            
            continue
        funcs.append(format_func_details(func_details))
    return funcs
def format_func_details(func_details, version=None, always_add_version=False):