Diagrams.TwoD.Arrowheads
tri
dart
spike
thorn
missile
noHead
arrowheadTriangle
arrowheadDart
arrowheadSpike
arrowheadThorn
arrowheadMissile
tri'
dart'
spike'
thorn'
missile'
noTail
quill
block
arrowtailQuill
arrowtailBlock
type ArrowHT