diff --git a/src/Multiset.java b/src/Multiset.java
new file mode 100644
index 0000000..82dd4fc
--- /dev/null
+++ b/src/Multiset.java
@@ -0,0 +1,25 @@
+public class Multiset {
+    public static boolean add(Object n) {
+        throw new java.lang.UnsupportedOperationException("Not implemented");
+    }
+
+    public static void remove(Object n) {
+        throw new java.lang.UnsupportedOperationException("Not implemented");
+    }
+
+    public static boolean contains(Object n) {
+        throw new java.lang.UnsupportedOperationException("Not implemented");
+    }
+
+    public static boolean isempty(Object n) {
+        throw new java.lang.UnsupportedOperationException("Not implemented");
+    }
+
+    public static int count(Object n) {
+        throw new java.lang.UnsupportedOperationException("Not implemented");
+    }
+
+    public static int size(Object n) {
+        throw new java.lang.UnsupportedOperationException("Not implemented");
+    }
+}