Si se especifica LoadByKeyOperation.InstanceIdForFreeKey, AcceptUninitializedInstance debe estar establecido en true. Si la clave está libre, se asociará a una instancia no inicializada con el identificador de instancia proporcionado.
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English version
If LoadByKeyOperation.InstanceIdForFreeKey is specified, AcceptUninitializedInstance must be set to true. If the key is free, it will be associated to an uninitialized instance with the instance ID provided.