public static Optional<String> resolveJavaVersionStringFromPath(Path home) {
		Optional<String> res = readJavaVersionStringFromReleaseFile(home);
		if (!res.isPresent()) {
			res = readJavaVersionStringFromJavaCommand(home);
		}
		return res;
	}
Returns the Path to JAVA_HOME

@return A Path pointing to JAVA_HOME or null if it isn't defined
src/main/java/dev/jbang/util/JavaUtil.java