Executable model compilation fails with 'inference variable A has incompatible bounds' when using accumulate

  when
  $max1 : Number() from accumulate(
    StockTick($time : dueDate);
    max($time.getTime().getTime()))

// object model:
public class StockTick {
...
    public Calendar getDueDate() {
        return dueDate;
    }

  reason: varargs mismatch; inference variable A has incompatible bounds
      equality constraints: java.lang.Long
      lower bounds: java.util.Date], Message [id=3, level=ERROR, path=src/main/java/defaultpkg/RulesE50E409E17279CAE524E8EC1D671D39BRuleMethods0.java, line=0, column=0