code: def log_snr_to_alpha_sigma(log_snr):
      return torch.sqrt(torch.sigmoid(log_snr)), torch.sqrt(
          torch.sigmoid(-log_snr)
      )
  
imports: import math
  from functools import partial, wraps
  import torch
  import torch.nn
  from einops import repeat
  from torch.special import expm1
  from nemo.collections.multimodal.parts.utils import randn_like
label_desc: Use image node_id 8 for calling a global function with example usage: log_snr_to_alpha_sigma(log_snr) and returns: torch,  torch