code: def peak_signal_noise_ratio() -> tuple:
      """Plot peak signal noise ratio example."""
      from torchmetrics.image.psnr import PeakSignalNoiseRatio
  
      p = lambda: torch.tensor([[0.0, 1.0], [2.0, 3.0]])
      t = lambda: torch.tensor([[3.0, 2.0], [1.0, 0.0]])
  
      # plot single value
      metric = PeakSignalNoiseRatio()
      metric.update(p(), t())
      fig, ax = metric.plot()
  
      # plot multiple values
      metric = PeakSignalNoiseRatio()
      vals = [metric(p(), t()) for _ in range(10)]
      fig, ax = metric.plot(vals)
  
      return fig, ax
  
imports: import argparse
  import matplotlib.pyplot
  import torch
label_desc: Use image node_id 13 for calling a global function with example usage: peak_signal_noise_ratio() and returns: fig,  ax