When profiling a test similar to ModuleVersionHandlerTestCase, it turns out that ModuleBootstrapTask.accept() results in 60 million String.append() operations.
That's because ModuleBootstrapTask.accept() is called number of modules times number of files in all JAR files, resulting in 20 million invocations.
A simple optimization brought execution time for our test down from 110s to 60s, only by caching the result of the String operation. Any Magnolia startup with empty repository should profit similarly from this optimizaton. Please find attached the optimized class.

Please consider an improvement here.