code: def shift(self, h=0, m=0, s=0, ms=0, frames=None, fps=None):
          
          delta = make_time(h=h, m=m, s=s, ms=ms, frames=frames, fps=fps)
          self.start += delta
          self.end += delta
docs: Shift start and end times.
  
          See :meth:`SSAFile.shift()` for full description.