This module contains legacy code support. Its purpose is to be included in old projects to avoid refactoring code. Legacy support is only valid up to the next major version. So for example this module is usable if you've got code written in 1.1 and want to switch to 1.7, but is unusable if you want to go from 1.1 to 2.0 or 2.2 etc.

When we say it's unusable we mean it. The 3.0 version of the legacy module will always be empty, because we will strip any 2.x legacy support from it (same for when we move from 1.x to 2.0 and any other major version). This is a helper to ensure fast turn around time. You should always aim to move your code to a state where you don't need to rely on this module for it to work.