paths
The 2D points which define the lines around the shape. This is a list of Path2d because a shape can have holes (so there's one path for the exterior, and one path for each hole). Also, a shape can be a compound of more than one exterior shape. e.g. If we have 2 circles (like a 'colon' symbol) we can define it using a single Shape2d with two paths.
Throws
NoPathsException
Some shapes have no paths data available within FooCAD. i.e. when the shape's geometry is only calculated within OpenSCAD.
In the early days of FooCAD, Union2d had no paths data, and so this would throw. That's no longer the case, and I think all 2d shapes now have paths.