public void CeilTest()
{
int[] arr = new int[] { 1, 4, 6, 8, 8, 15, 21 };
Assert.Equal(0, BinartSearchClass.Ceil(arr, -10000));
Assert.Equal(0, BinartSearchClass.Ceil(arr, 1));
Assert.Equal(4, BinartSearchClass.Ceil(arr, 8));
Assert.Equal(5, BinartSearchClass.Ceil(arr, 10));
Assert.Equal(-1, BinartSearchClass.Ceil(arr, 25));
}