title: Nesting simpleType within complexType
body: <p>The code below gives me the following error during validation. Does it mean that I cannot nest simpleType elements within complexType elements? </p>
  
  <p><code>Error - Line 18, 17: org.xml.sax.SAXParseException; lineNumber: 18; columnNumber: 17; s4s-elt-must-match.1: The content of 'sequence' must match (annotation?, (element | group | choice | sequence | any)*). A problem was found starting at: simpleType.</code></p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;schema xmlns="http://www.w3.org/2001/XMLSchema" 
      targetNamespace="http://www.example.org/carType"
      elementFormDefault="qualified"&gt;
  
      &lt;element name="carType"&gt;
          &lt;complexType&gt;
              &lt;sequence&gt;
                  &lt;simpleType name="colour"&gt;
                      &lt;restriction base="string"&gt;
                          &lt;enumeration value="blue" /&gt;
                          &lt;enumeration value="yellow" /&gt;
                          &lt;enumeration value="green" /&gt;
                          &lt;enumeration value="black" /&gt;
                          &lt;enumeration value="white" /&gt;
                      &lt;/restriction&gt;
                  &lt;/simpleType&gt;
                  &lt;simpleType name="body"&gt;
                      &lt;restriction base="string"&gt;
                          &lt;enumeration value="sedan" /&gt;
                          &lt;enumeration value="hatchback" /&gt;
                      &lt;/restriction&gt;
                  &lt;/simpleType&gt;
              &lt;/sequence&gt;
          &lt;/complexType&gt;
      &lt;/element&gt;
  &lt;/schema&gt;
  </code></pre>