f return_dict is True, SchedulerOutput is returned, otherwise a
tuple is returned where the first element is the sample tensor.
  Predict the sample from the previous timestep by reversing the SDE. This function propagates the sample with
the multistep DPMSolver.  SchedulerOutput  class diffusers.schedulers.scheduling_utils.SchedulerOutput  < source > ( prev_sample: FloatTensor  )   Parameters   prev_sample (torch.FloatTensor of shape (batch_si