def transform(self, offset):
assert self._start + offset > <NUM_LIT:0>,('<STR_LIT>'<EOL>'<STR_LIT>'.format(offset, self._start+offset, self._end+offset))<EOL>self._start += offset<EOL>self._end += offset<EOL>
Shift this range by the specified offset.

Note: the resulting range must be a valid interval.