def with_fps(self, fps, change_duration=False):
        """Returns a copy of the clip with a new default fps for functions like
        write_videofile, iterframe, etc.

        Parameters
        ----------

        fps : int
          New ``fps`` attribute value for the clip.

        change_duration : bool, optional
          If ``change_duration=True``, then the video speed will change to
          match the new fps (conserving all frames 1:1). For example, if the
          fps is halved in this mode, the duration will be doubled.
        """
        if change_duration:
            from moviepy.video.fx.MultiplySpeed import MultiplySpeed

            newclip = self.with_effects([MultiplySpeed(fps / self.fps)])
        else:
            newclip = self.copy()

        newclip.fps = fps
        return newclip
Returns a copy of the clip with a new default fps for functions like
        write_videofile, iterframe, etc.

        Parameters
        ----------

        fps : int
          New ``fps`` attribute value for the clip.

        change_duration : bool, optional
          If ``change_duration=True``, then the video speed will change to
          match the new fps (conserving all frames 1:1). For example, if the
          fps is halved in this mode, the duration will be doubled.
        
moviepy/Clip.py