code: def delete(self,removed):
          
          sql = "DELETE FROM %s " %self.name
          if isinstance(removed,dict):
              # remove a single record
              _id = removed['__id__']
              sql += "WHERE rowid = ?"
              args = (_id,)
          else:
              # convert iterable into a list (to be able to sort it)
              removed = [ r for r in removed ]
              if not removed:
                  return 0
              args = [ r['__id__'] for r in removed ]
              sql += "WHERE rowid IN (%s)" %(','.join(['?']*len(args)))
          self.cursor.execute(sql,args)
          return len(removed)
docs: Remove a single record, or the records in an iterable
          Before starting deletion, test if all records are in the base
          and don't have twice the same __id__
          Return the number of deleted items