in mps-maven-plugin/src/main/java/org/jetbrains/mps/mavenplugin/GenerateJavaMojo.java [145:157]
private Collection<File> getJars(Collection<File> roots) {
List<File> jars = new ArrayList<>();
for (File root : roots) {
if (root.isFile()) {
jars.add(root);
} else if (root.isDirectory()) {
jars.addAll(FileUtils.listFiles(root, new String[]{"jar"}, true));
}
}
return jars;
}