code: def get_mult(self, h, r, t, t_next, previous_sigma):
      mult1 = to_sigma(t_next) / to_sigma(t)
      mult2 = (-h).expm1()
  
      if previous_sigma is not None:
          mult3 = 1 + 1 / (2 * r)
          mult4 = 1 / (2 * r)
          return mult1, mult2, mult3, mult4
      else:
          return mult1, mult2
  
imports: from typing import Dict, Union
  import torch
  from omegaconf import ListConfig, OmegaConf
  from tqdm import tqdm
  from ...modules.diffusionmodules.sampling_utils import get_ancestral_step, linear_multistep_coeff, to_d, to_neg_log_sigma, to_sigma
  from ...util import append_dims, default, instantiate_from_config
label_desc: Use image node_id 2 for calling the DPMPP2MSampler obj's underlying member method code with example usage: obj.get_mult(h, r, t, t_next, previous_sigma) and returns: mult1,  mult2,  mult3,  mult4, mult1,  mult2