A linear ring is a closed LineString with four or more positions.
The first and last positions are equivalent, and they MUST contain identical values; their representation SHOULD also be identical.
A linear ring is the boundary of a surface or the boundary of a hole in a surface.
A linear ring MUST follow the right-hand rule with respect to the area it bounds, i.e., exterior rings are counterclockwise, and holes are clockwise.
List[Position]