def __add__(self, other: Optional['AverageMetric']) -> 'AverageMetric':
    if (other is None):
        return self
    full_numer: TScalar = (self._numer + other._numer)
    full_denom: TScalar = (self._denom + other._denom)
    return type(self)(numer=full_numer, denom=full_denom)
def __add__(self, other: Optional['AverageMetric']) -> 'AverageMetric':
    if (other is None):
        return self
    full_numer: TScalar = (self._numer + other._numer)
    full_denom: TScalar = (self._denom + other._denom)
    return type(self)(numer=full_numer, denom=full_denom)