public void TestExponentiate()
{
Assert.True(Math_.IsIntegerPowerOfTen(+0));
Assert.True(Math_.IsIntegerPowerOfTen(-0));
Assert.True(Math_.IsIntegerPowerOfTen(-1));
Assert.True(Math_.IsIntegerPowerOfTen(+4));
Assert.True(Math_.IsIntegerPowerOfTen(+20));
Assert.True(Math_.IsIntegerPowerOfTen(-40));
Assert.True(Math_.IsIntegerPowerOfTen(+90000000000000L));
Assert.True(Math_.IsIntegerPowerOfTen(-90000000000000L));
Assert.False(Math_.IsIntegerPowerOfTen(+21));
Assert.False(Math_.IsIntegerPowerOfTen(-42));
Assert.False(Math_.IsIntegerPowerOfTen(+90000000000001L));
Assert.False(Math_.IsIntegerPowerOfTen(-90000000000002L));
Assert.Equal(new long[] { 80, 100, 20000, 400000, 7000000, 10000000 }, Math_.Exponentiate(17420180));
Assert.Equal(new long[] { 200000 }, Math_.Exponentiate(200000));
Assert.Equal(new long[] { -400 }, Math_.Exponentiate(-400));
Assert.Equal(new long[] { 0xa0, 0xf00, 0x1000 }, Math_.Exponentiate(0x1fa0, 16));
Assert.Equal(new long[] { 0b10, 0b1000, 0b10000, 0b1000000 }, Math_.Exponentiate(0x5a, 2));