Bases: abjad.core.interface._Interface, abjad.core.grobhandler._GrobHandler
Handle LilyPond TupletNumber grob.
abjad> t = Staff(construct.scale(4))
abjad> t.tupletnumber.transparent = True
abjad> print t.format
\new Staff \with {
\override TupletNumber #'transparent = ##t
} {
c'8
d'8
e'8
f'8
}