public Object visit(ImportDirective node) {
            String packageName = node.getName();
            mHasImports = true;
            LinkedHashSet<String> importSet =
                new LinkedHashSet<String>(Arrays.asList(mImports));
            if (! importSet.contains(packageName)) {
                importSet.add(packageName);
                mImports = importSet.toArray(new String[importSet.size()]);
            }
            return null;
        }