Function estimate_hurst_exponent 

pub fn estimate_hurst_exponent<T>(
    signal: &Signal<T>,
    wavelet: &dyn Wavelet,
    config: Option<MultifractalConfig>,
) -> Result<HurstResult>
where
    T: SignalType + Float + FromPrimitive + AddAssign + SubAssign + MulAssign + DivAssign + 'static,