Why can't I save this SalesForce Batchable class? -

i using apex workbook refresh knowledge of salesforce.

tutorial #15, lesson 1: offers following code:

global class cleanuprecords implements database.batchable<object> {     global final string query;      global cleanuprecords (string q) {query = q;}      global database.querylocator start (database.batchablecontext bc)     {            return database.getquerylocator(query);     }           global void execute (database.batchablecontext bc, list<sobject> scope)     {         delete scope;         database.emptyrecyclebin(scope);     }          global void finish(database.batchablecontext bc)     {         asyncapexjob = [                 select id, status, numberoferrors, jobitemsprocessed, totaljobitems, createdby.email                 asyncapexjob                  id = :bc.getjobid()             ];          // send email apex job's submitter         // notifying of job completion.         messaging.singleemailmessage mail = new messaging.singleemailmessage();         string[] toaddresses = new string[] {a.createdby.email};         mail.settoaddresses(toaddresses);         mail.setsubject('record clean completed ' + a.status);         mail.setplaintextbody (                 'the batch apex job processed ' + a.totaljobitems +                 ' batches '+ a.numberoferrors + ' failures.'                );         messaging.sendemail(new messaging.singleemailmessage[] { mail });     }  } 

however, regardless of development interface (e.g. force ide, console, setup) use, when try save this, get:

multiple markers @ line     - file saved locally, not server     - save error: cleanuprecords: class must implement global interface method: iterable<object> start(database.batchablecontext) database.batchable<object>, cleanuprecords: class must implement global interface method: void execute(database.batchablecontext, list<object>)       database.batchable<object> 

(or equivalent, depending upon how try save it.)

however, seems me required methods there.

what's missing?

prepare frustrated ... there's 1 character off.

your class declaration should be:

global class cleanuprecords implements database.batchable<sobject> { 

instead of:

global class cleanuprecords implements database.batchable<object> {