def bandreject(self, frequency, width_q=<NUM_LIT>):
if not is_number(frequency) or frequency <= <NUM_LIT:0>:<EOL><INDENT>raise ValueError("<STR_LIT>")<EOL><DEDENT>if not is_number(width_q) or width_q <= <NUM_LIT:0>:<EOL><INDENT>raise ValueError("<STR_LIT>")<EOL><DEDENT>effect_args = [<EOL>'<STR_LIT>', '<STR_LIT>'.format(frequency), '<STR_LIT>'.format(width_q)<EOL>]<EOL>self.effects.extend(effect_args)<EOL>self.effects_log.append('<STR_LIT>')<EOL>return self<EOL>
Apply a two-pole Butterworth band-reject filter with the given
        central frequency, and (3dB-point) band-width. The filter rolls off at
        6dB per octave (20dB per decade) and is described in detail in
        http://musicdsp.org/files/Audio-EQ-Cookbook.txt

        Parameters
        ----------
        frequency : float
            The filter's center frequency in Hz.
        width_q : float, default=2.0
            The filter's width as a Q-factor.
        constant_skirt : bool, default=False
            If True, selects constant skirt gain (peak gain = width_q).
            If False, selects constant 0dB peak gain.

        See Also
        --------
        bandreject, sinc