Find the volume generated by rotating the region bounded by y=ex\displaystyle {y}={e}^{{-{{x}}}} , y=0\displaystyle {y}={0} , x=1\displaystyle {x}=-{1}x=0\displaystyle {x}={0}  about the line x=3.\displaystyle {x}={3}.  Express your answer in exact form.

Volume =