[interest invokers] Should el.interestTargetElement return null when not supported?

[lukewarlow]

trafficstars

Similar question applies to el.invokeTargetElement.

If I put interesttarget on a div and then do div.interestTargetElement which should it return?

Currently invokeTargetElement "works" for submit buttons in so much as it returns a non null value. Is this correct?

[lukewarlow]

No longer relevant (for agenda) as the property is only exposed where supported now (except for the submit button case but that's less important imo)