returns the result of interpreting the object as an instance of ` document root ' . this implementation returns null ; returning a non-null result will terminate the switch . concode_field_sep Bz288963Package modelPackage concode_field_sep T caseBook concode_elem_sep T caseIndentedpara concode_elem_sep T doSwitch concode_elem_sep T doSwitch concode_elem_sep T doSwitch concode_elem_sep T caseParagraph concode_elem_sep T defaultCase concode_elem_sep T caseFootnote
T function ( DocumentRoot arg0 ) { return null ; }