Represents a bag used in the XACML spec as return values from functions and designators/selectors that provide more than one value. All values in the bag are of the same type, and the bag may be empty. The bag is immutable, although its contents may not be.
NOTE: This is the one standard attribute type that can't be created from the factory, since you can't have this in an XML block (it is used only in return values & dynamic inputs). I think this is right, but we may need to add some functionality to let this go into the factory.
@since 1.0
@author Seth Proctor
@author Steve HannaAdding generic type support by Christian Mueller (geotools)