@Test
public void shouldReturnPrimeForClosestOfAPrime()
{

    assertThat(Primes.closestPrimeTo(2), is(2));
    assertThat(Primes.closestPrimeTo(3), is(3));
    assertThat(Primes.closestPrimeTo(5), is(5));
    assertThat(Primes.closestPrimeTo(7), is(7));
}