class_docstr: Tool to maintain statistical data in a window.
      
code: def __init__(self, window_size):
      self.items = [None] * window_size
      self.idx = 0
      self.count = 0
  
imports: import numpy
label_desc: Use image node_id 1 to create a new WindowStat object from inherited base classes: object with example: obj = WindowStat(window_size)