I proposed to create a base class which the existing abstract classes AbstractRandomGenerator and BitsStreamGenerator will extend.
This would allow to define nextBytes(byte) at the base class level.
The code for that method is almost identical in the two hierarchies: they only differ in a call to either nextInt() or next(32) respectively; the latter is however the same as the former, in disguise, and is not subject to change given the type of return value.
As a corollary, the new base class can be the unique place where to add utilities such as the one proposed in
Update: AbstractRandomGenerator and BitsStreamGenerator are both obsoleted by the class proposed in this report.