 empty text nodes. 
 </li>
 <li> it is expected that the <code>value</code> and 
 <code>nodeValue</code> attributes of an <code>Attr</code> node initially 
 return the <a href='http://www.w3.org/TR/2004/REC-xml-20040204#AVNormalize'>XML 1.0 
 normalized value</a>. However, if the parameters "<a href='http://www.w3.org/TR/DOM-Level-3-Core/core.html#parameter-validate-if-schema'>
 validate-if-schema</a>" and "<a href='http://www.w3.org/TR/DOM-Level-3-Core/core.html#parameter-datatype-normalization'>
 datatype