backport IJetDecorator to 21.2
the IJetDecorator is also useful in r21.2. only one change is necessary w.r.t. the version aiming for r22: the return types need to be int to conform to the r21.2 IJetModifier interface.
Edited by Chris Pollard
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the IJetDecorator is also useful in r21.2. only one change is necessary w.r.t. the version aiming for r22: the return types need to be int to conform to the r21.2 IJetModifier interface.