class_docstr: Keeps track of mean and standard deviation for some value.
code: def reset(self):
      self.n = 0
      self.sum = 0.0
      self.var = 0.0
      self.val = 0.0
      self.mean = np.nan
      self.mean_old = 0.0
      self.m_s = 0.0
      self.std = np.nan
  
imports: import numpy
  from .None import meter
label_desc: Use image node_id 4 for calling the AverageValueMeter obj's underlying member method code with example usage: obj.reset() without return types