LazyClassLoader (@Nullable Iterable<? extends File> files, ClassLoader parent) { return Iterators.isEmptyCollection(files)? null : new LazyClassLoader(Iterators.map(files, new Function<File, URL>() { @Override public URL fun(File f) { try { return f.toURI().toURL(); } catch (MalformedURLException e) { throw new AssertionError(e); } } }), parent); }