code: def BCD_calc(TOP, P, AM):
      
      try:
          TOP_sum = sum(TOP.values())
          P_sum = sum(P.values())
          return abs(AM) / (P_sum + TOP_sum)
      except Exception:
          return "None"
docs: Calculate BCD (Bray-Curtis dissimilarity).
  
      :param TOP: test outcome positive
      :type TOP : dict
      :param P: condition positive
      :type P : dict
      :param AM: Automatic/Manual
      :type AM : int
      :return: BCD as float