CAVEAT: the interruptible region could not be properly combined with swimlanes in MagicDraw, the "containment" of the swimlanes by the interruptible region in the image below is graphically contrived.

ADVICE: avoid the contrived placement of object flows on swimlane partitions as shown in the SysML1.0 sample figure, it is graphically unstable ! Prefer instead typed, named, input/output pin pairs (which can be stereotyped as <<continuous>>). You can even allocate meaningfully to/from the pins. In general, I advise MD SysML and MagicDraw UML users to adopt Pin pairs over ObjectFlows wherever possible!

Image: