Is it at all acceptable to have nested public interfaces?
<p>I have several interfaces all with only a single method and they are all very similar. I know it works, but should I or should I not group them like this:</p>

<pre><code>public class InterfaceGroup {
    public interface Type1 {
        public void method(int a);
    }
    public interface Type2 {
        public void method(String s);
    }
    public interface Type3 {
        public void method();
    }
}
</code></pre>

<p>And then reference them externally as <code>InterfaceGroup.Type1</code>.</p>
