New in version 2.3.
True when expr is a component with clef mark attached:
abjad> staff = Staff("c'8 d'8 e'8 f'8")
abjad> contexttools.ClefMark('treble')(staff)
ClefMark('treble')(Staff{4})
abjad> f(staff)
\new Staff {
\clef "treble"
c'8
d'8
e'8
f'8
}
abjad> contexttools.is_component_with_clef_mark_attached(staff)
True
False otherwise:
abjad> contexttools.is_component_with_clef_mark_attached(staff[0]) False
Return boolean.