process.   Returns 
torch.FloatTensor
  
The sample tensor at the previous timestep.
  One step for the first-order DPMSolver (equivalent to DDIM).  multistep_dpm_solver_second_order_update  < source > ( model_output_list: List *args sample: FloatTensor = None noise: Optional = None **kwargs  ) → torch.FloatTensor  Parameters   model_output_list (List[torch.FloatTensor]) —
The direct outputs from learned diffusion model at current and latter ti