code: def calc_psnr(x: torch.Tensor, y: torch.Tensor):
      """
      Calculates the Peak-signal-to-noise ratio between tensors `x` and `y`.
      """
      mse = calc_mse(x, y)
      psnr = -10.0 * torch.log10(mse)
      return psnr
  
label_desc: Use image node_id 2 for calling a global function with example usage: calc_psnr(x, y) and returns: psnr