File srcDir = new File(args[0]);
File outputDir = new File(args[1]);
File[] files = srcDir.listFiles();
if (files != null) {
extClasses = new HashMap<String, ExtClass>();
compilationUnitModelRegistry = new CompilationUnitModelRegistry();
interfaces = new HashSet<String>();
for (File jsonFile : files) {
ExtClass extClass = readExtApiJson(jsonFile);
if (extClass != null) {
extClasses.put(extClass.name, extClass);