javadoc. Add return annotation.
javadoc. Add return annotation.

git-svn-id: https://svn.apache.org/repos/asf/jmeter/trunk@1719540 13f79535-47bb-0310-9956-ffa450edef68

Former-commit-id: fd1b5796a08afa636cff8847bbc2caa63bbedcb7
ham1/jmeter,benbenw/jmeter,apache/jmeter,benbenw/jmeter,etnetera/jmeter,apache/jmeter,ham1/jmeter,etnetera/jmeter,benbenw/jmeter,ham1/jmeter,ham1/jmeter,benbenw/jmeter,apache/jmeter,etnetera/jmeter,etnetera/jmeter,etnetera/jmeter,apache/jmeter,apache/jmeter,ham1/jmeter