code: def init_providers(self, provider, kwargs):
          
          self.provider = notifiers.get_notifier(provider, strict=True)
          if kwargs.get("fallback"):
              self.fallback = notifiers.get_notifier(kwargs.pop("fallback"), strict=True)
              self.fallback_defaults = kwargs.pop("fallback_defaults", {})
docs: Inits main and fallback provider if relevant
  
          :param provider: Provider name to use
          :param kwargs: Additional kwargs
          :raises ValueError: If provider name or fallback names are not valid providers, a :exc:`ValueError` will
           be raised