Private - Answer the anIndex-th item of the hash table for the receiver.
Using this instead of basicAt: allows for easier changes in the
representation
primAt: anIndex put: value
Private - Store value in the anIndex-th item of the hash table for the
receiver. Using this instead of basicAt:put: allows for easier
changes in the representation
primSize
Private - Answer the size of the hash table for the receiver.
Using this instead of basicSize allows for easier changes
in the representation