Code Currently Implemented
The following classes have been replaced or modified by this addon
Q. Should I install this addon?
If you have built an addon which utilises external libraries that rely on Guzzle6, you can use this library to provide support for Guzzle6.
For everyone else - you are better off using the built in Guzzle5 functionality shipped in the core for maximum compatibility with the core product and other addons. There is nothing wrong with Guzzle5 - it works perfectly well for most purposes.
If you are building a new addon that needs to make external HTTP calls, I suggest you just use the core Guzzle5 functionality.