How to check if a property exists in ASL?

Dear all,

I was looking at the docs and couldn't find an answer to this question:

How can I check if a property exists within an object using ASL?

I have certain instances of a Router where I added a custom property.

Now I need to check if it exists and tried options like

if (memI->OverrunCpuUtilThreshold>0)

if (!isNull(memI->OverrunCpuUtilThreshold))

with no luck, since most of the operations and functions seem to be object related and not property.

Do you know of a way to check if a certain property exists within an object?

Thank you in advance,

H.