6.1.4.1. VirtualBox. In the case of VirtualBox the fact that the web
API is generated from the same interface as other statically linked
APIs provides an early indication that no special care is taken
regarding the web API. This is further fueled by a web API which
suffers from a severe case of the multi-service anti-pattern where
the web API and all its 1888 methods (and respective request and
response types) from different business entities are provided under
one single class. Perhaps as a result of this, and to the fact that the
backwards compatibility responsibility has been delegated fully to
the client side, the main client for this web API (phpVirtualBox)
simply disregards the issue of backwards compatibility by releasing a new version for each of the VirtualBox releases. From the code
analysis performed on VirtualBox it has also arisen that every single
major and minor version has pushed breaking changes to the web
API which reveals a great deal of external instability. Furthermore,
the association rules mined out of the source code showed that multiple core implementation files consistently change together with
the web API, revealing a potentially high fan-in between implementation and web API