docs: def longest_strike_below_mean(x):
      """
      Returns the length of the longest consecutive subsequence in x that is smaller than the mean of x
  
      :param x: the time series to calculate the feature of
      :type x: numpy.ndarray
      :return: the value of this feature
      :return type: float
      """
      if not isinstance(x, (np.ndarray, pd.Series)):
          x = np.asarray(x)
      return np.max(_get_length_sequences_where(x <= np.mean(x))) if x.size > 0 else 0