question: returns the result of interpreting the object as an instance of ` children books ' . this implementation returns null ; returning a non-null result will terminate the switch . concode_field_sep TestPackage modelPackage concode_field_sep T caseLibrary concode_elem_sep T caseResourceLink concode_elem_sep T doSwitch concode_elem_sep T doSwitch concode_elem_sep T doSwitch concode_elem_sep T caseAdultBooks concode_elem_sep T caseBookDefinitionResourceLink concode_elem_sep T casePublisherDefinition concode_elem_sep T caseDocumentRoot concode_elem_sep T caseBookDefinition concode_elem_sep T caseBooksInLib concode_elem_sep T defaultCase
target: T function ( ChildrenBooks arg0 ) { return null ; }