The current JMS messages test includes both JMS message bodies and JMS message headers and properties. The test is structured in a way that all the headers and properties test run on each of the JMS body combinations. This results in an excessively long test, and does not improve coverage.
By splitting the tests into a separate JMS message test and JMS headers/properties test, this problem can be eliminated. The message test will be far shorter and can specialize its tests for message bodies; similarly the headers/properties test can also specialize. Any expansion of the number of tests won't result in a massive increase in the number of tests that run (as is currently the case).