class_docstr: Incremental version of https://en.wikipedia.org/wiki/Kahan_summation_algorithm
code: def __init__(self):
      self.partials = []
  
file_path: vowpal_wabbit/python/tests/confidence_sequence.py
imports: from cmath import sqrt
label_desc: Use image node_id 1 to create a new incremental_f_sum object  with example: obj = incremental_f_sum()