[rules-users] Issue with Accumulate

[Mohod, Akash]

Hi,
I have a Map object that maps User product type experience with the level of expertise. I am trying to use accumulate in my rule
Such that if the user has experience with certain product then it gets the experience level and sums it up .
I am using Drools 5.1 , mvel 2, spring batch 2.x.
This is my rule :-

rule "Insert Product Types"
dialect "mvel"
salience 1800
when
    eval (true)
then
    ProductType p1 = new ProductType();
    p1.setName("P1");
    ProductType p2 = new ProductType();
    p2.setName("P2");
    insert (p1);
    insert (p2);
end


rule "Product Class Experience"
dialect "mvel"
salience 1600
when
    ProductType ($name : name)
    $total : Number () from accumulate (
                       Client (productExperience.keySet contains $name, $score : productExperience[$name]),
                        sum($score))
  then
    System.out.println ("Product Type Score " + $total);

End

When the rule is fired I get the attached exception .

Any suggestions / help will be great.
Regards,
Akash


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