applicationId 
  An optional application specific identifier. When set it will be appended to the User-Agent header of every request in the form of: app/{applicationId}. When not explicitly set, the value will be loaded from the following locations:
- JVM System Property: - aws.userAgentAppId
- Environment variable: - AWS_SDK_UA_APP_ID
- Shared configuration profile attribute: - sdk_ua_app_id
See shared configuration settings reference for more information on environment variables and shared config settings.