private Predicate<String> getClassNameMatchPredicate() {
        String classNameRegexStr = heapHistogramConfigProvider.get().getClassNameMatchRegex();

        if (classNameRegexStr == null || classNameRegexStr.isEmpty()) {
            //no prop value so return an always true predicate
            return str -> true;
        } else {
            try {
                return Pattern.compile(classNameRegexStr).asPredicate();
            } catch (final RuntimeException e) {
                throw new RuntimeException(
                        LogUtil.message("Error compiling regex string [{}]", classNameRegexStr), e);
            }
        }
    }
Generates a heap histogram using the 'gcClassHistogram' MBean action.  Will
block until the action completes/fails.
list of {@link HeapHistogramEntry}
stroom-node/stroom-node-impl/src/main/java/stroom/node/impl/HeapHistogramService.java