returns the result of interpretting the object as an instance of ` document root ' . this implementation returns null ; returning a non-null result will terminate the switch . concode_field_sep MixedPackage modelPackage concode_elem_sep String copyright concode_field_sep T caseLetterBodyType concode_elem_sep T caseSalutationType concode_elem_sep T doSwitch concode_elem_sep T doSwitch concode_elem_sep T doSwitch concode_elem_sep T defaultCase
T function ( DocumentRoot arg0 ) { return null ; }