javadoc: fill in return and throws tags
javadoc: fill in return and throws tags

git-svn-id: https://svn.apache.org/repos/asf/jmeter/trunk@1822378 13f79535-47bb-0310-9956-ffa450edef68

Former-commit-id: c0763da75b37396555b1fc5328b80bf97be67c56
etnetera/jmeter,benbenw/jmeter,apache/jmeter,etnetera/jmeter,apache/jmeter,apache/jmeter,etnetera/jmeter,benbenw/jmeter,ham1/jmeter,ham1/jmeter,ham1/jmeter,ham1/jmeter,etnetera/jmeter,benbenw/jmeter,etnetera/jmeter,apache/jmeter,ham1/jmeter,benbenw/jmeter,apache/jmeter