_mean: FloatTensor  )   Parameters   prev_sample (torch.FloatTensor of shape (batch_size, num_channels, height, width) for images) —
Computed sample (x_{t-1}) of previous timestep. prev_sample should be used as next model input in the
denoising loop.   prev_sample_mean (torch.FloatTensor of shape (batch_size, num_channels, height, width) for images) —
Mean averaged prev_sample over previous timesteps.    Output class for the scheduler’s step fu