Introduced the ModelElementCollection class.
Used concrete types instead of IDbSet<T>.
Introduced the new IRepository interface and modified some types.
Implemented Identity<T>.
Implemented Identity<TKey1, TKey2>
Introduced IUnitOfWork2.
Renamed Identity to Id.
Introduced ExecuteQueryAsync and renamed some members.
Addressed that some slow tests are run only on CI.
Introduced members of IModelElementCommand.
Introduced ArticleElement.
Implemented the Execute method.
Introduced the IParameter interface.
Implemented Parameter.
Introduced EqualPredicate.
Implemented the EqualPredicate class.
Addressed case-insensitive for equality of Parameter.
Removed IModelElement<TModel>.
Implemented ArticleElement.
Updated Experiment packages to v2.1.3.