Class holding boundary attributes.
This class is used for the attributes associated with the nodes of region boundary shell trees returned by the {@link Region#getTree(boolean) Region.getTree(includeBoundaryAttributes)}when the boolean {@code includeBoundaryAttributes} parameter isset to {@code true}. It contains the parts of the node cut sub-hyperplane that belong to the boundary.
This class is a simple placeholder, it does not provide any processing methods.
@param < S> Type of the space.
@see Region#getTree
@since 3.0