code: def reset(self):
      self.tp = None
      self.fp = None
      self.tn = None
      self.fn = None
      self.size = None
      self.test_empty = None
      self.test_full = None
      self.reference_empty = None
      self.reference_full = None
  
imports: import numpy
  from medpy import metric
label_desc: Use image node_id 4 for calling the ConfusionMatrix obj's underlying member method code with example usage: obj.reset() without return types