[Debugging] Most methods implementations consist of "throw new RuntimeException()" statement

For much of the Java libraries provided by MicroEJ, when browsing the classes source code, the method implementations show this statement, yet at runtime they operate properly.

This is because the involved class is part of the so-called foundation libraries, which actual implementation is either hardware-dependent or relying on core runtime APIs.

See Section 3.4 Foundation vs Add-On Libraries in StandaloneApplicationDeveloperGuide for more details.