title: why xsd schema cannot validate string length with restriction maxLength
body: <p>I'm developping a web service SOAP and I've defined my xsd schema and wsdl file, in which I want to validate the element <code>comment</code> (whose type is string) by fixing his max length. But when I validate the request with SoapUI, It seems to me the xsd schema doesn't validate the string max length.</p>
  
  <p>This below is the syntax of my xsd schema : </p>
  
  <pre><code>&lt;xsd:element name="comment" minOccurs="0"&gt;
      &lt;xsd:simpleType&gt;
          &lt;xsd:restriction base="xsd:string"&gt;
              &lt;xsd:maxLength value="20"/&gt;
          &lt;/xsd:restriction&gt;
      &lt;/xsd:simpleType&gt;
  &lt;/xsd:element&gt;
  </code></pre>
  
  <p>Anyone knows why? Thanks in advance.</p>