class_docstr: Tool to maintain statistical data in a window.
      
code: def max(self):
      if self.count > 0:
          return np.max(self.items[: self.count])
      else:
          return None
  
imports: import numpy
label_desc: Use image node_id 5 for calling the WindowStat obj's underlying member method code with example usage: obj.max() and returns: np, None