     source = '''
       <!doctype html
       <html
-        @lang en
         <head
           </meta
-            @charset utf-8
+            @charset UTF-8
           <title
-            TITLE
+            b-html example
         <body
-          <!--comment
-          <h1
-            @class title
-            HEADLINE
+          <!--comment example
           <p
             Hello, b-html!
-            >@bouzuya
-            </img
-              @alt sample image
-              @src /images/sample.png
+            <a
+              @href https://github.com/bouzuya
+              >@bouzuya
     '''
-    assert bHtml(source) is '<!DOCTYPE html><html lang="en"><head><meta charset="utf-8" /><title>TITLE</title></head><body><!--comment--><h1 class="title">HEADLINE</h1><p>Hello, b-html!@bouzuya<img alt="sample image" src="/images/sample.png" /></p></body></html>'
+    assert bHtml(source) is '<!DOCTYPE html><html><head><meta charset="UTF-8" /><title>b-html example</title></head><body><!--comment example--><p>Hello, b-html!<a href="https://github.com/bouzuya">@bouzuya</a></p></body></html>'
     assert bHtml(source, format: 'demo') is '''
       <!DOCTYPE html>
-      <html
-        lang="en"
-        >
+      <html>
         <head>
           <meta
-            charset="utf-8"
+            charset="UTF-8"
             />
           <title>
-            TITLE
+            b-html example
           </title>
         </head>
         <body>
-          <!--comment-->
-          <h1
-            class="title"
-            >
-            HEADLINE
-          </h1>
+          <!--comment example-->
           <p>
             Hello, b-html!
-            @bouzuya
-            <img
-              alt="sample image"
-              src="/images/sample.png"
-              />
+            <a
+              href="https://github.com/bouzuya"
+              >
+              @bouzuya
+            </a>
           </p>
         </body>
       </html>

      assert nodes[0].value is 'html'
      assert nodes[1].type is 'element'
      assert nodes[1].name is 'html'
      assert nodes[1].attributes.length is 1
      assert nodes[1].attributes[0].type is 'attribute'
      assert nodes[1].attributes[0].name is 'lang'
      assert nodes[1].attributes[0].value is 'en'
      assert nodes[1].children.length is 2
      head = nodes[1].children[0]
      assert head.type is 'element'

      assert head.children[0].attributes.length is 1
      assert head.children[0].attributes[0].type is 'attribute'
      assert head.children[0].attributes[0].name is 'charset'
      assert head.children[0].attributes[0].value is 'UTF-8'
      assert head.children[0].children.length is 0
      assert head.children[1].name is 'title'
      assert head.children[1].attributes.length is 0
      assert head.children[1].children.length is 1
      assert head.children[1].children[0].type is 'text'
      assert head.children[1].children[0].value is 'b-html example'
      body = nodes[1].children[1]
      assert body.type is 'element'
      assert body.name is 'body'
      assert body.attributes.length is 0
      assert body.children.length is 2
      assert body.children[0].type is 'comment'
      assert body.children[0].value is 'comment example'
      assert body.children[1].type is 'element'
      assert body.children[1].name is 'p'
      assert body.children[1].attributes.length is 0
      assert body.children[1].children.length is 2
      assert body.children[1].children[0].type is 'text'
      assert body.children[1].children[0].value is 'Hello, b-html!'
      a = body.children[1].children[1]
      assert a.type is 'element'
      assert a.name is 'a'
      assert a.attributes.length is 1
      assert a.attributes[0].type is 'attribute'
      assert a.attributes[0].name is 'href'
      assert a.attributes[0].value is 'https://github.com/bouzuya'
      assert a.children.length is 1
      assert a.children[0].type is 'text'
      assert a.children[0].value is '@bouzuya'
      assert.deepEqual options, { format }
    bHtml source, { format }
