WebDSL views the [Int] as a subtype of [Object], the generated Java code does not.

[javac] The method countList_Object__(List<Object>) in the type countList_Object__ is not applicable for the arguments (List<Integer>)

Different issue, but same cause (WebDSL subtyping vs Java subtyping) as https://yellowgrass.org/issue/WebDSL/840

Submitted by Daco Harkes on 3 June 2015 at 11:35

Same cause, other error in generated Java code: incompatible types: List<AssignmentCollectionSubmission> cannot be converted to List<AssignmentSubmission>.

Work around: wrap with list comprehension that casts: AssignmentSubmission.getGradeData([ (a as AssignmentSubmission) | a in x]).