AirDirection
Direction of an :class:Air note (and air long notes), as a readable string.
Attributes
attributeUP= 'up'attributeDOWN= 'down'attributeUP_LEFT= 'up_left'attributeUP_RIGHT= 'up_right'attributeDOWN_LEFT= 'down_left'attributeDOWN_RIGHT= 'down_right'