Enum to denote the type of break found. New line, space etc.
Values:
UNKNOWN (0):
Unknown break label type.
SPACE (1):
Regular space.
SURE_SPACE (2):
Sure space (very wide).
EOL_SURE_SPACE (3):
Line-wrapping break.
HYPHEN (4):
End-line hyphen that is not present in text; does not
co-occur with SPACE, LEADER_SPACE, or
LINE_BREAK.
LINE_BREAK (5):
Line break that ends a paragraph.
