Calculate RACCU (Random accuracy unbiased).

    :param TOP: test outcome positive
    :type TOP : int
    :param P: condition positive
    :type P : int
    :param POP: population
    :type POP : int
    :return: RACCU as float

def RACCU_calc(TOP, P, POP):
    """
    Calculate RACCU (Random accuracy unbiased).

    :param TOP: test outcome positive
    :type TOP : int
    :param P: condition positive
    :type P : int
    :param POP: population
    :type POP : int
    :return: RACCU as float
    """
    try:
        result = ((TOP + P) / (2 * POP))**2
        return result
    except Exception:
        return "None"