class_docstr: Incremental version of https://en.wikipedia.org/wiki/Kahan_summation_algorithm
code: def __add__(self, other):
      result = incremental_f_sum()
      result.partials = deepcopy(self.partials)
      for y in other.partials:
          result += y
      return result
  
file_path: vowpal_wabbit/python/tests/confidence_sequence.py
imports: from cmath import sqrt
label_desc: Use image node_id 3 for calling the incremental_f_sum obj's underlying member method code with example usage: obj.__add__(other) and returns: result