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//  Copyright (C) 2016-2018 Ericsson. All rights reserved.
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// This file is licensed under the CREATIVE COMMONS ATTRIBUTION 4.0 INTERNATIONAL LICENSE
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// @author Sven van der Meer (sven.van.der.meer@ericsson.com)
//

== Concept: DataType

Data types are tightly controlled in APEX in order to provide a very high degree of consistency in policies and to facilitate tracking of changes to context as policies execute.
All context is modeled as a __DataType__ concept.
Each DataType concept instance is keyed with an `ArtifactKey` key.
The DataType field identifies the Java class of objects that is used to represent concept instances that use this data type.
All context has a __DataType__; incoming and outgoing context is represented by __EventField__ concepts and all other context is represented by __ContextItem__ concepts.