Javadoc: Add missing @throws tag.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/fileupload/trunk@1565250 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/src/main/java/org/apache/commons/fileupload/util/mime/Base64Decoder.java b/src/main/java/org/apache/commons/fileupload/util/mime/Base64Decoder.java
index 1ccabd8..07b089e 100644
--- a/src/main/java/org/apache/commons/fileupload/util/mime/Base64Decoder.java
+++ b/src/main/java/org/apache/commons/fileupload/util/mime/Base64Decoder.java
@@ -101,6 +101,7 @@
      * @param out the output stream to hold the decoded bytes
      *
      * @return the number of bytes produced.
+     * @throws IOException thrown when the padding is incorrect or the input is truncated.
      */
     public static int decode(byte[] data, OutputStream out) throws IOException {
         int        outLen = 0;