Types
		
			
			
				Represents presence of a value
					
					
				
				
						- Box
							 - 
							A box which might (FullBox) or might not (EmptyBox) contain a value
						
Methods
							
							
							
							
							
							
							
							init(b:FullBox, *args:Arr)
							
							Do not use directly!
							Helper constructor that throws InvalidArgument when
							FullBox is created with zero or more than one argument.