Corresponds to the following XML document:
<book language="en" author="Ernest Hemingway">
<title>A Farewell to Arms</title>
<chapter>
<heading>Chapter One</heading>
<paragraph> ... <paragraph>
<paragraph> ... <paragraph>
</chapter>
<chapter>
<heading>Chapter Two</heading>
<paragraph> ... <paragraph>
<paragraph> ... <paragraph>
</chapter>
</book>