Add missing IOUtils test

Author: Gary Gregory

src/test/java/org/apache/commons/io/IOUtilsTest.java

@@ -49,6 +49,7 @@
 import java.net.Socket;
 import java.net.URI;
 import java.net.URL;
+import java.net.URLConnection;
 import java.nio.ByteBuffer;
 import java.nio.channels.FileChannel;
 import java.nio.channels.Selector;
@@ -441,6 +442,13 @@ public synchronized void close() throws IOException {
         });
     }
 
+    @Test
+    public void testCloseURLConnection() {
+        assertDoesNotThrow(() -> IOUtils.close((URLConnection) null));
+        assertDoesNotThrow(() -> IOUtils.close(new URL("https://www.apache.org/").openConnection()));
+        assertDoesNotThrow(() -> IOUtils.close(new URL("file:///").openConnection()));
+    }
+
     @Test
     public void testConstants() {
         assertEquals('/', IOUtils.DIR_SEPARATOR_UNIX);