function Rules(injector) {
  this._commandStack = injector.get('commandStack', false);
}
A service that provides rules for certain diagram actions.

The default implementation will hook into the {@link CommandStack}
to perform the actual rule evaluation. Make sure to provide the
`commandStack` service with this module if you plan to use it.

Together with this implementation you may use the {@link import('./RuleProvider').default}
to implement your own rule checkers.

This module is ment to be easily replaced, thus the tiny foot print.

@param {Injector} injector