content: from typing import *
  
  
  class GuidanceIntervalSamplerMixin:
      """
      A mixin class for samplers that apply classifier-free guidance with interval.
      """
  
      def _inference_model(self, model, x_t, t, cond, neg_cond, cfg_strength, cfg_interval, **kwargs):
          if cfg_interval[0] <= t <= cfg_interval[1]:
              pred = super()._inference_model(model, x_t, t, cond, **kwargs)
              neg_pred = super()._inference_model(model, x_t, t, neg_cond, **kwargs)
              return (1 + cfg_strength) * pred - cfg_strength * neg_pred
          else:
              return super()._inference_model(model, x_t, t, cond, **kwargs)
  