ignore false-positive from pmd

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/collections/trunk@1476593 13f79535-47bb-0310-9956-ffa450edef68
Fix jira-report, snippet taken from commons-math.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/collections/trunk@1476594 13f79535-47bb-0310-9956-ffa450edef68