cleanup

test/attributes/AttributeTest.java

@@ -1,6 +1,7 @@
 package j2html.test.attributes;
 
 import j2html.src.attributes.Attribute;
+import j2html.src.tags.ContainerTag;
 import org.junit.Test;
 
 import static org.junit.Assert.assertTrue;
@@ -19,4 +20,12 @@ public class AttributeTest {
         assertTrue(nullAttribute.render().equals(""));
     }
 
+    @Test
+    public void testSetAttribute() throws Exception {
+        ContainerTag testTag = new ContainerTag("a");
+        testTag.setAttribute("href", "http://example.com");
+        testTag.setAttribute("href", "http://example.org");
+        assertTrue(testTag.render().equals("<a href=\"http://example.org\"></a>"));
+    }
+
 }