@Domain.Include
Indicates that a field or method must contribute to the metamodel.
For mixins is also allowed to be placed on the mixin’s main method.
By placing the Domain.Include annotation on a method or field, a contract with the meta-model is enforced, such that this class-member must be recognized by the meta-model and cannot be ignored. Meta-model validation will fail when this contract is violated.
Acts as the semantic counterpart to Domain.Exclude .