Many tests expect stderr to be empty and to report a failure if that is not the case, so we have stdErrShouldbeEmpty function. But then we found that some tests, at times, could be impacted by deprecated features, so we added stderrShouldBeEmptyIgnoreDeprecatedWarnings. And some tests could encounter other warnings (unrelated to correct operation of the test) so we have the more general stderrShouldBeEmptyIgnoreVMWarnings, and even more general stderrShouldBeEmptyIgnoreWarnings.

Ignoring all warnings could mask an actual problem however, so we would like to have finer-grained control. Rather than try to support the various kinds of warnings that might impact tests (motivation here is the large-page allocation failure warning) we should provide a general "ignore" method that takes a regex of what to ignore (and which can then be used by the existing methods as appropriate).