returns the result of interpreting the object as an instance of ` purchase order ' . this implementation returns null ; returning a non-null result will terminate the switch . concode_field_sep ModelgroupPackage modelPackage concode_field_sep T caseOrderList concode_elem_sep T doSwitch concode_elem_sep T doSwitch concode_elem_sep T doSwitch concode_elem_sep T defaultCase
T function ( PurchaseOrder arg0 ) { return null ; }