Java Random nextInt(int) method [duplicate]

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• Implementation of java.util.Random.nextInt 2 answers

While reading the documentation of nextInt(int) method in Random class, i didn't understand what is the meaning of the following paragraph :

The algorithm is slightly tricky. It rejects values that would result in an uneven distribution (due to the fact that 2^31 is not divisible by n). The probability of a value being rejected depends on n. The worst case is n=2^30+1, for which the probability of a reject is 1/2, and the expected number of iterations before the loop terminates is 2.

can anyone give me an example of a number that will be rejected by nextInt(int) method ?

Source Random class documentation.