code: def register():
      '''Register the plugin only if required signals are available'''
      for sig_name in _SIGNAL_HANDLERS_DB.keys():
          if not hasattr(signals, sig_name):
              _LOGGER.error((
                  'The i18n_subsites plugin requires the {} '
                  'signal available for sure in Pelican 3.4.0 and later, '
                  'plugin will not be used.').format(sig_name))
              return
  
      for sig_name, handler in _SIGNAL_HANDLERS_DB.items():
          sig = getattr(signals, sig_name)
          sig.connect(handlerf register():
      '''Register the plugin only if required signals are available'''
      for sig_name in _SIGNAL_HANDLERS_DB.keys():
          if not hasattr(signals, sig_name):
              _LOGGER.error((
                  'The i18n_subsites plugin requires the {} '
                  'signal available for sure in Pelican 3.4.0 and later, '
                  'plugin will not be used.').format(sig_name))
              return
  
      for sig_name, handler in _SIGNAL_HANDLERS_DB.items():
          sig = getattr(signals, sig_name)
          sig.connect(handler)
docs: Register the plugin only if required signals are available