class_docstr: Keeps track of mean and standard deviation of some value for a given window.
code: def value(self):
      n = min(self.n, self.windowsize)
      mean = self.sum / max(1, n)
      std = math.sqrt(
          max((self.var - n * mean * mean) / max(1, n - 1), 0)
      )
      return mean, std
  
file_path: pywick/pywick/meters/movingaveragevaluemeter.py
imports: import math
  from .None import meter
  import torch
label_desc: Use image node_id 4 for calling the MovingAverageValueMeter obj's underlying member method code with example usage: obj.value() and returns: mean,  std