code: def zero_disk(self, disk_xml=None):
          
  
          troubled_disks = 0
          for filer_disk in disk_xml:
              raid_state = filer_disk.find('raid-state').text
              if not raid_state == 'spare':
                  continue
              is_zeroed = filer_disk.find('is-zeroed').text
  
              if is_zeroed == 'false':
                  troubled_disks += 1
          self.push('not_zeroed', 'disk', troubled_disks)
docs: Collector and publish not zeroed disk metrics