This role turns an exception into a control exception, such as CX::Next or CX::Take. It has got no code other than the definition.
Since Rakudo 2019.03, throwing an object that mixes in this role X::Control can raise a control exception which is caught by the CONTROL phaser instead of CATCH. This allows to define custom control exceptions.
For example, the custom CX::Oops control exception we define below: