@@ -0,0 +1,237 @@
+package com.denver.citiestate.interfaces;%0A%0Apublic interface Listable %7B%0A%09/**%0A%09 * %0A%09 * @param other%0A%09 * @return%0A%09 */%0A%09public abstract int compareTo(Listable other);%0A%0A%09/**%0A%09 * %0A%09 * @return Listable%0A%09 */%0A%09public abstract Listable copy();%0A%0A%7D%0A

Add Listable interface to the project