Add missing (direct usage) tests.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/codec/trunk@1754052 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/src/test/java/org/apache/commons/codec/binary/HexTest.java b/src/test/java/org/apache/commons/codec/binary/HexTest.java
index de928aa..3dc37c7 100644
--- a/src/test/java/org/apache/commons/codec/binary/HexTest.java
+++ b/src/test/java/org/apache/commons/codec/binary/HexTest.java
@@ -437,12 +437,24 @@
     }
 
     @Test
-    public void testEncodeHexByteBufferZeroes() {
+    public void testEncodeHex_ByteBufferOfZeroes() {
         final char[] c = Hex.encodeHex(ByteBuffer.allocate(36));
         assertEquals("000000000000000000000000000000000000000000000000000000000000000000000000", new String(c));
     }
 
     @Test
+    public void testEncodeHexByteString_ByteBufferOfZeroes() {
+        final String c = Hex.encodeHexString(ByteBuffer.allocate(36));
+        assertEquals("000000000000000000000000000000000000000000000000000000000000000000000000", c);
+    }
+
+    @Test
+    public void testEncodeHexByteString_ByteArrayOfZeroes() {
+        final String c = Hex.encodeHexString(new byte[36]);
+        assertEquals("000000000000000000000000000000000000000000000000000000000000000000000000", c);
+    }
+
+    @Test
     public void testEncodeStringEmpty() throws EncoderException {
         assertTrue(Arrays.equals(new char[0], (char[]) new Hex().encode("")));
     }