code: def _apply_offset(self, offset):
          
          if not isinstance(offset, TimeValue):
              self.log_exc(u"offset is not an instance of TimeValue", None, True, TypeError)
          self.log([u"Applying offset %s", offset])
          self.smflist.offset(offset)
docs: Apply the given offset (negative, zero, or positive)
          to all time intervals.
  
          :param offset: the offset, in seconds
          :type  offset: :class:`~aeneas.exacttiming.TimeValue`