Depreacte FilenameUtils 0-argument contructor
diff --git a/src/main/java/org/apache/commons/io/FilenameUtils.java b/src/main/java/org/apache/commons/io/FilenameUtils.java
index 162b6cd..d3ead56 100644
--- a/src/main/java/org/apache/commons/io/FilenameUtils.java
+++ b/src/main/java/org/apache/commons/io/FilenameUtils.java
@@ -1718,7 +1718,11 @@
 
     /**
      * Instances should NOT be constructed in standard programming.
+     *
+     * @deprecated TODO Make private in 4.0.
      */
+    @Deprecated
     public FilenameUtils() {
+        // empty
     }
 }