The EnsureWorkbookModel element specifies the input data for the EnsureWorkbookModel WSDL operation.

 <xs:element name="EnsureWorkbookModel" xmlns:xs="http://www.w3.org/2001/XMLSchema">
       <xs:element minOccurs="0" maxOccurs="1" name="sessionId" type="xs:string"/>

sessionId: A session identifier. MUST be present. SHOULD have a value that has been obtained from a previous call to the OpenWorkbook, OpenWorkbookEx, OpenWorkbookForEditing, or NewWorkbook operations, but MAY instead be obtained in any other way.