It would be nice to have the ability to use OOPath in accumulate functions. E.g. sum(/fact/property).

Example of a rule:

import org.drools.compiler.oopath.*;
global java.lang.Object globalVar
rule R when
accumulate ( Adult() ; $accumulateResult: sum(/children/age) )
then
kcontext.getKieRuntime().setGlobal(\"globalVar\", $accumulateResult);
end