Spring added private constructor as per the design

Comment From: abhishek-abhi

Hi, @sbrannen please review my PR and kindly merge if it is okay.

Comment From: snicoll

@abhishek-abhi the class is abstract so there is no need to add a private constructor there.

As we've mentioned to you in the Spring Boot project, if you're trying to contribute, please find an existing issue or ask questions before starting.