Scale tuplet contents by power of two if tuplet multiplier less than 1/2 or greater than 2. Return tuplet.
abjad> tuplet = tuplettools.FixedDurationTuplet(Duration(2, 8), "c'4 d'4 e'4")
abjad> tuplet
FixedDurationTuplet(1/4, [c'4, d'4, e'4])
abjad> tuplettools.fix_contents_of_tuplets_in_expr(tuplet)
FixedDurationTuplet(1/4, [c'8, d'8, e'8])
Changed in version 2.0: renamed tuplettools.contents_fix() to tuplettools.fix_contents_of_tuplets_in_expr().