This partial class contains common connectors needed for wheel
models. In particular, frame_a is intended to
connected a wheel carrier (also called upright) and
flange_a to connect a driveline. This class
should be extended to create a proper model, see e.g.
IdealWheelJoint model.
Note: the loss power has to be provided by an equation in the model which inherits from this partial model, such as
WheelInterfaces model(lossPower = ...).