Minor Description
As of LUCENE-5604 (committed to v4.8), StringHelper will initialize GOOD_FAST_HASH_SEED based on the system property "tests.seed" if it is set. Unfortunately it doesn't do an empty-string check, and it's common at least in my setup that copies Lucene's maven pom.xml that the string will be empty unless I set it on the command line. FWIW Randomized Testing does do an empty-string check.