code: def get_r(
      self,
  ):
      return self.tp / (self.fn + self.tp)
  
imports: import logging
  import numpy
  from collections import Counter, defaultdict
  from scipy.optimize import linear_sum_assignment
  from .blanc import blanc, tuple_to_metric
label_desc: Use image node_id 4 for calling the NEREvaluator obj's underlying member method code with example usage: obj.get_r() and returns: unknown