used by project --&gt;
        &lt;xs:element name="components"     type="ComponentsType"   minOccurs="1" /&gt;
        &lt;!-- project modules/source files not contained in components --&gt;
        &lt;xs:element name="files"          type="FilesType"        minOccurs="0"/&gt;
      &lt;/xs:all&gt;
      &lt;!-- schema version used by writer --&gt;
      &lt;xs:attribute name="schemaVersion"  type="SchemaVersionType" use="required" /&gt;
    &lt;/xs:complexType&gt;
  &lt;/xs:element&gt;
&lt;/xs:schema&gt;