Why can't I find the Amazon S3 class in the latest version 2.3.5 version of zend framework?

I have the direct download link for zend framework,

http://ift.tt/1AwDxOh

I've downloaded it and across the internet people show tutorials of how to use the amazon s3 class to save files directly to s3. However, I cannot find the amazon s3 class for some reason. Was it recently removed from the zend framework?