def to_line_string(self, closed=True):
from imgaug.augmentables.lines import LineString<EOL>if not closed or len(self.exterior) <= <NUM_LIT:1>:<EOL><INDENT>return LineString(self.exterior, label=self.label)<EOL><DEDENT>return LineString(<EOL>np.concatenate([self.exterior, self.exterior[<NUM_LIT:0>:<NUM_LIT:1>, :]], axis=<NUM_LIT:0>),<EOL>label=self.label)<EOL>
Convert this polygon's `exterior` to a ``LineString`` instance.

Parameters
----------
closed : bool, optional
    Whether to close the line string, i.e. to add the first point of
    the `exterior` also as the last point at the end of the line string.
    This has no effect if the polygon has a single point or zero
    points.

Returns
-------
imgaug.augmentables.lines.LineString
    Exterior of the polygon as a line string.