Implementation of GroupWithAttributes that simply delegates to an underlying Group and Attributes object.
Instances of this class will be effectively immutable so long as either:
- It is constructed with immutable objects.
- The mutable objects it is constructed with are not "leaked".
CompareTo must be compatible with the equals() and hashCode() methods
||the object to be compared.
- a negative integer, zero, or a positive integer as this object
is less than, equal to, or greater than the specified object.