let's say you have 2 strings, "jim", "joe" which have the same hash value, collision resolution gets both into the hash table.
A new string "jay" also happens to have the same hash value. Looking up with via hash key tells me it exists, but I never put it in. Another question, how do you prevent another entry of "jim" to end up in the table - since collsion resolution will find a place for it.
I don't see this aspect of hashing covered in chapter 9.