docs: def quantile(x, q):
      """
      Calculates the q quantile of x. This is the value of x greater than q% of the ordered values from x.
  
      :param x: the time series to calculate the feature of
      :type x: numpy.ndarray
      :param q: the quantile to calculate
      :type q: float
      :return: the value of this feature
      :return type: float
      """
      x = pd.Series(x)
      return pd.Series.quantile(x, q)