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- constants - we hold here classes like AwesomePluginConstants.java and maybe some model enums that are plugin specific.
- hooks - model and view hooks like: ViewNameViewHooksViewNameHooks.java, ModelNameHooks.java. If the hook class is meant to extend (on a business level) an other plugin it should have plugin abbreviation for ex. ModelNameHooksAP.java
- validators - model validators like: ModelNameValidators.java, SomeOtherModelNameValidators.java or ModelNameValidatorsAP.java (like with the hooks)
- listeners - view listeners like: ViewNameListeners.java, ViewNameListenersAP.java (like with the hooks)
- states - if there is some logic regarding model states (I consider enum state model field as something that common to write it here), for ex. ModelNameStatesService.java
- workPlansColumnExtension - http://wiki.qcadoo.org/display/QCDMESDOC/WorkPlans+column+extension
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