diff --git a/docs/1.4/api/index.html b/docs/1.4/api/index.html
index 522f8da..68590d0 100644
--- a/docs/1.4/api/index.html
+++ b/docs/1.4/api/index.html
@@ -21,21 +21,21 @@
     <title>API :: Eclipse Hono&trade; Vers.: 1.4</title>
 
     
-    <link href="/hono/docs/css/nucleus.css?1626138727" rel="stylesheet">
-    <link href="/hono/docs/css/fontawesome-all.min.css?1626138727" rel="stylesheet">
-    <link href="/hono/docs/css/hybrid.css?1626138727" rel="stylesheet">
-    <link href="/hono/docs/css/featherlight.min.css?1626138727" rel="stylesheet">
-    <link href="/hono/docs/css/perfect-scrollbar.min.css?1626138727" rel="stylesheet">
-    <link href="/hono/docs/css/auto-complete.css?1626138727" rel="stylesheet">
-    <link href="/hono/docs/css/atom-one-dark-reasonable.css?1626138727" rel="stylesheet">
-    <link href="/hono/docs/css/theme.css?1626138727" rel="stylesheet">
-    <link href="/hono/docs/css/hugo-theme.css?1626138727" rel="stylesheet">
+    <link href="/hono/docs/css/nucleus.css?1626225107" rel="stylesheet">
+    <link href="/hono/docs/css/fontawesome-all.min.css?1626225107" rel="stylesheet">
+    <link href="/hono/docs/css/hybrid.css?1626225107" rel="stylesheet">
+    <link href="/hono/docs/css/featherlight.min.css?1626225107" rel="stylesheet">
+    <link href="/hono/docs/css/perfect-scrollbar.min.css?1626225107" rel="stylesheet">
+    <link href="/hono/docs/css/auto-complete.css?1626225107" rel="stylesheet">
+    <link href="/hono/docs/css/atom-one-dark-reasonable.css?1626225107" rel="stylesheet">
+    <link href="/hono/docs/css/theme.css?1626225107" rel="stylesheet">
+    <link href="/hono/docs/css/hugo-theme.css?1626225107" rel="stylesheet">
     
-    <link href="/hono/docs/css/theme-hono.css?1626138727" rel="stylesheet">
+    <link href="/hono/docs/css/theme-hono.css?1626225107" rel="stylesheet">
     
-    <link href="/hono/docs/css/hono.css?1626138727" rel="stylesheet">
+    <link href="/hono/docs/css/hono.css?1626225107" rel="stylesheet">
 
-    <script src="/hono/docs/js/jquery-3.3.1.min.js?1626138727"></script>
+    <script src="/hono/docs/js/jquery-3.3.1.min.js?1626225107"></script>
 
     <style>
       :root #header + #content > #left > #rlblock_left{
@@ -83,14 +83,14 @@
     <span data-search-clear=""><i class="fas fa-times"></i></span>
 </div>
 
-<script type="text/javascript" src="/hono/docs/js/lunr.min.js?1626138727"></script>
-<script type="text/javascript" src="/hono/docs/js/auto-complete.js?1626138727"></script>
+<script type="text/javascript" src="/hono/docs/js/lunr.min.js?1626225107"></script>
+<script type="text/javascript" src="/hono/docs/js/auto-complete.js?1626225107"></script>
 <script type="text/javascript">
     
         var baseurl = "https:\/\/www.eclipse.org\/hono\/docs\/\/1.4";
     
 </script>
-<script type="text/javascript" src="/hono/docs/js/search.js?1626138727"></script>
+<script type="text/javascript" src="/hono/docs/js/search.js?1626225107"></script>
 
     
   </div>
@@ -1456,7 +1456,41 @@
                   
                     
                     
-                      <option id="stable" value="https://www.eclipse.org/hono/docs/api/">stable (1.8)</option>
+                      <option id="stable" value="https://www.eclipse.org/hono/docs/api/">stable (1.9)</option>
+                    
+                  
+              
+                  
+              
+                  
+              
+                  
+              
+                  
+              
+                  
+              
+                  
+              
+                  
+              
+                  
+              
+                  
+              
+                  
+              
+                  
+              
+          
+              
+              
+                  
+              
+                  
+                    
+                    
+                      <option id="1.9" value="https://www.eclipse.org/hono/docs/1.9/api/">1.9</option>
                     
                   
               
@@ -1486,6 +1520,8 @@
                   
               
                   
+              
+                  
                     
                     
                       <option id="1.8" value="https://www.eclipse.org/hono/docs/1.8/api/">1.8</option>
@@ -1518,6 +1554,8 @@
                   
               
                   
+              
+                  
                     
                     
                       <option id="1.7" value="https://www.eclipse.org/hono/docs/1.7/api/">1.7</option>
@@ -1550,6 +1588,8 @@
                   
               
                   
+              
+                  
                     
                     
                       <option id="1.6" value="https://www.eclipse.org/hono/docs/1.6/api/">1.6</option>
@@ -1582,6 +1622,8 @@
                   
               
                   
+              
+                  
                     
                     
                       <option id="1.5" value="https://www.eclipse.org/hono/docs/1.5/api/">1.5</option>
@@ -1614,6 +1656,8 @@
                   
               
                   
+              
+                  
                     
                     
                       <option id="1.4" value="https://www.eclipse.org/hono/docs/1.4/api/" selected>1.4</option>
@@ -1646,6 +1690,8 @@
                   
               
                   
+              
+                  
                     
                     
                       <option id="1.3" value="https://www.eclipse.org/hono/docs/1.3/api/">1.3</option>
@@ -1678,6 +1724,8 @@
                   
               
                   
+              
+                  
                     
                     
                       <option id="1.2" value="https://www.eclipse.org/hono/docs/1.2/api/">1.2</option>
@@ -1710,6 +1758,8 @@
                   
               
                   
+              
+                  
                     
                     
                       <option id="1.1" value="https://www.eclipse.org/hono/docs/1.1/api/">1.1</option>
@@ -1742,6 +1792,8 @@
                   
               
                   
+              
+                  
                     
                     
                       <option id="1.0" value="https://www.eclipse.org/hono/docs/1.0/api/">1.0</option>
@@ -1774,6 +1826,8 @@
                   
               
                   
+              
+                  
                     
                     
                       <option id="dev" value="https://www.eclipse.org/hono/docs/dev/api/">dev</option>
@@ -2897,19 +2951,19 @@
     <div style="left: -1000px; overflow: scroll; position: absolute; top: -1000px; border: none; box-sizing: content-box; height: 200px; margin: 0px; padding: 0px; width: 200px;">
       <div style="border: none; box-sizing: content-box; height: 200px; margin: 0px; padding: 0px; width: 200px;"></div>
     </div>
-    <script src="/hono/docs/js/clipboard.min.js?1626138728"></script>
-    <script src="/hono/docs/js/perfect-scrollbar.min.js?1626138728"></script>
-    <script src="/hono/docs/js/perfect-scrollbar.jquery.min.js?1626138728"></script>
-    <script src="/hono/docs/js/jquery.sticky.js?1626138728"></script>
-    <script src="/hono/docs/js/featherlight.min.js?1626138728"></script>
-    <script src="/hono/docs/js/highlight.pack.js?1626138728"></script>
+    <script src="/hono/docs/js/clipboard.min.js?1626225108"></script>
+    <script src="/hono/docs/js/perfect-scrollbar.min.js?1626225108"></script>
+    <script src="/hono/docs/js/perfect-scrollbar.jquery.min.js?1626225108"></script>
+    <script src="/hono/docs/js/jquery.sticky.js?1626225108"></script>
+    <script src="/hono/docs/js/featherlight.min.js?1626225108"></script>
+    <script src="/hono/docs/js/highlight.pack.js?1626225108"></script>
     <script>hljs.initHighlightingOnLoad();</script>
-    <script src="/hono/docs/js/modernizr.custom-3.6.0.js?1626138728"></script>
-    <script src="/hono/docs/js/learn.js?1626138728"></script>
-    <script src="/hono/docs/js/hugo-learn.js?1626138728"></script>
+    <script src="/hono/docs/js/modernizr.custom-3.6.0.js?1626225108"></script>
+    <script src="/hono/docs/js/learn.js?1626225108"></script>
+    <script src="/hono/docs/js/hugo-learn.js?1626225108"></script>
 
-    <link href="/hono/docs/mermaid/mermaid.css?1626138728" rel="stylesheet" />
-    <script src="/hono/docs/mermaid/mermaid.js?1626138728"></script>
+    <link href="/hono/docs/mermaid/mermaid.css?1626225108" rel="stylesheet" />
+    <script src="/hono/docs/mermaid/mermaid.js?1626225108"></script>
     <script>
         mermaid.initialize({ startOnLoad: true });
     </script>