def METHOD_NAME(self, freq_min=None, freq_max=None, tolerance=1e-8):
    """Set frequeny range where moment is computed."""
    if freq_min is None:
        self._fmin = tolerance
    else:
        self._fmin = freq_min - tolerance
    if freq_max is None:
        self._fmax = np.max(self._frequencies) + tolerance
    else:
        self._fmax = freq_max + tolerance