@Override
  public void accumulate(Object value) {
    if (value != null && value != QueryService.UNDEFINED) {
      Number number = (Number) value;
      result += number.doubleValue();
    }
  }
Computes the sum for replicated & PR based queries.
geode-core/src/main/java/org/apache/geode/cache/query/internal/aggregate/Sum.java