Affects Version/s: 1.2, 2.0, 2.1, 2.2
Fix Version/s: 3.0
The static field ChiSquareTestImpl.distribution serves no purpose.
There is a setter for it, but in every case where the field is used, it is first overwritten with a new value.
The field and the setter should be removed, and the methods that create a new instance should create a local variable instead.
For Math 2.1, the field can be removed and the setter deprecated.