@property<EOL><INDENT>def is_valid(self):<DEDENT>
if len(self.exterior) < <NUM_LIT:3>:<EOL><INDENT>return False<EOL><DEDENT>return self.to_shapely_polygon().is_valid<EOL>
Estimate whether the polygon has a valid shape.

To to be considered valid, the polygons must be made up of at least 3 points and have concave shape.
Multiple consecutive points are allowed to have the same coordinates.

Returns
-------
bool
    True if polygon has at least 3 points and is concave, otherwise False.