[O] How to use xml src block as data input?

[stardiviner]

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I have a xml src block like this:

#+NAME: xml-sample
#+begin_src xml
<?xml version="1.0" encoding="utf-8"?>
<feed xmlns="http://www.w3.org/2005/Atom";>

  <title>Example Feed</title>
  <link href="http://example.org/"/>
  <updated>2003-12-13T18:30:02Z</updated>
  <author>
    <name>John Doe</name>
  </author>
  <id>urn:uuid:60a76c80-d399-11d9-b93C-0003939e0af6</id>

  <entry>
    <title>Atom-Powered Robots Run Amok</title>
    <link rel="alternate" href="http://example.org/2003/12/13/atom03"/>
    <id>urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a</id>
    <updated>2003-12-13T18:30:02Z</updated>
    <summary>Some text.</summary>
  </entry>

</feed>
#+end_src

How can I use this xml data as input in another src block?

I tried like this:

#+begin_src emacs-lisp :var sample=xml-sample
(elfeed-xml-parse-region sample)
#+end_src

But it reports no org-babel-execute for xml!
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