How to programmatically reset an application property?

[Ron Cecchini]

I'm using Camel + Spring Boot.

In my application.properties, I set a property 'foo.bar.size'

In my routes, I use:  {{foo.bar.size}}

In some Java processor code, I use:  
camelContext.resolvePropertyPlaceholders("{{foo.bar.size}}")

I now need to reset that property in some Java code and have it take effect 
immediately.

I read the "Properties" doc and tried a couple of things... but I'm missing the 
magic sauce.

How do I reset an application property?

Thank you very much.