The processing of properties for the creation of an EntityManager do not properly handle simple value types that can be augmented by parenthesized configuration options.
Map propMap = new HashMap();
EntityManager em = emf.createEntityManager(propMap);
actually results in the creation of an EntityManager instance where the Query SQL Cache is disabled. This is because the entire value, "true(EnableStatistics=true)" is passed into Strings.parse() which returns the result of a Boolean.valueOf() operation. Since "true" doesn't match "true(EnableStatistics=true)", the call to parse() returns false - so in this case, the QuerySQLCache property is set to false causing it to be disabled for that instance of EntityManager.