AWS::SQS::ReceivedMessage in Version 2 of the AWS SDK for Ruby

Anybody know where AWS::SQS::ReceivedMessage has gone in new version of aws-sdk! I was doing some testing (http://ift.tt/1zz4YsT). I am using aws-sdk-core-2.0.21 and AWS::SQS::ReceivedMessage is not there. What can I do for the test? or How can I find the replacement. I cannot find anything useful in change logs and upgrade notes.