Add a test for #17

Author: cowtowncoder

src/test/java/com/fasterxml/jackson/dataformat/smile/ObjectIdTest.java

@@ -0,0 +1,27 @@
+package com.fasterxml.jackson.dataformat.smile;
+
+import com.fasterxml.jackson.annotation.*;
+import com.fasterxml.jackson.databind.*;
+
+public class ObjectIdTest extends SmileTestBase
+{
+    @JsonIdentityInfo(generator = ObjectIdGenerators.UUIDGenerator.class, property = "@id")
+    public static class D {
+        public D next;
+    }
+
+    // [Issue#19]
+    public void testObjectIdAsUUID() throws Exception
+    {
+        ObjectMapper mapper = smileMapper();
+        D d = new D();
+        d.next = d;
+
+        mapper.enable(SerializationFeature.INDENT_OUTPUT);
+        byte[] smile = mapper.writeValueAsBytes(d);
+
+        D de = mapper.readValue(smile, D.class);
+        assertNotNull(de);
+        assertSame(de, de.next);
+    }
+}