docs: def update(self, process_list):
          """Update the AMP"""
          # Get the systemctl status
          logger.debug('{}: Update stats using systemctl {}'.format(self.NAME, self.get('systemctl_cmd')))
          try:
              res = check_output(self.get('systemctl_cmd').split())
          except (OSError, CalledProcessError) as e:
              logger.debug('{}: Error while executing systemctl ({})'.format(self.NAME, e))
          else:
              status = {}
              # For each line
              for r in to_ascii(res).split('\n')[1:-8]:
                  # Split per space .*
                  column = r.split()
                  if len(column) > 3:
                      # load column
                      for c in range(1, 3):
                          try:
                              status[column[c]] += 1
                          except KeyError:
                              status[column[c]] = 1
              # Build the output (string) message
              output = 'Services\n'
              for k, v in iteritems(status):
                  output += '{}: {}\n'.format(k, v)
              self.set_result(output, separator=' ')
  
          return self.result()