Moontoast\Math\BigNumberTest::testSubtract PHP Method

    public function testSubtract()
    {
        $bn = new BigNumber(2147483647);
        $this->assertSame($bn, $bn->subtract('9223372036854775808'));
        $this->assertSame('-9223372034707292161', $bn->getValue());
        $bn->setScale(3);
        $this->assertSame('-9223372034707292163.250', $bn->subtract(2.25)->getValue());
    }