Define the :class:`~geographiclib.polygonarea.PolygonArea` class
The constructor initializes a empty polygon. The available methods are
* :meth:`~geographiclib.polygonarea.PolygonArea.Clear` reset the
polygon
* :meth:`~geographiclib.polygonarea.PolygonArea.AddPoint` add a vertex
to the polygon
* :meth:`~geographiclib.polygonarea.PolygonArea.AddEdge` add an edge
to the polygon
* :meth:`~geographiclib.polygonarea.PolygonArea.Compute` compute the
properties of the polygon
* :meth:`~geographiclib.polygonarea.PolygonArea.TestPoint` compute the
properties of the polygon with a tentative additional vertex
* :meth:`~geographiclib.polygonarea.PolygonArea.TestEdge` compute the
properties of the polygon with a tentative additional edge
The public attributes for this class are
* :attr:`~geographiclib.polygonarea.PolygonArea.earth`
:attr:`~geographiclib.polygonarea.PolygonArea.polyline`
:attr:`~geographiclib.polygonarea.PolygonArea.area0`
:attr:`~geographiclib.polygonarea.PolygonArea.num`
:attr:`~geographiclib.polygonarea.PolygonArea.lat1`
:attr:`~geographiclib.polygonarea.PolygonArea.lon1`