is class.
 
 <pre>
 &lt;complexType name="SiteInvestigatorType">
   &lt;complexContent>
     &lt;extension base="{http://schema.integration.caaers.cabig.nci.nih.gov/common}SiteInvestigatorType">
       &lt;sequence>
         &lt;element ref="{http://schema.integration.caaers.cabig.nci.nih.gov/common}organizationRef"/>
         &lt;element name="startDate" type="{http://www.w3.org/2001/XMLSchema}date"/>
         &lt;element name="endDate" type="{http://www.w3.org/2001/XMLSchema}date" minOccurs="0"/>
       &