Add unit test for TrieUtils.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/collections/trunk@1540644 13f79535-47bb-0310-9956-ffa450edef68

src/test/java/org/apache/commons/collections4/TrieUtilsTest.java

@@ -0,0 +1,56 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.commons.collections4;
+
+import junit.framework.Test;
+
+import org.apache.commons.collections4.trie.PatriciaTrie;
+import org.apache.commons.collections4.trie.UnmodifiableTrie;
+
+/**
+ * Tests for TrieUtils factory methods.
+ *
+ * @version $Id$
+ */
+public class TrieUtilsTest extends BulkTest {
+
+    public TrieUtilsTest(final String name) {
+        super(name);
+    }
+
+
+    public static Test suite() {
+        return BulkTest.makeSuite(TrieUtilsTest.class);
+    }
+
+    //----------------------------------------------------------------------
+
+    public void testUnmodifiableTrie() {
+        Trie<String, Object> trie = TrieUtils.unmodifiableTrie(new PatriciaTrie<Object>());
+        assertTrue("Returned object should be an UnmodifiableTrie.",
+            trie instanceof UnmodifiableTrie);
+        try {
+            TrieUtils.unmodifiableTrie(null);
+            fail("Expecting IllegalArgumentException for null trie.");
+        } catch (final IllegalArgumentException ex) {
+            // expected
+        }
+    }
+
+}
+
+