System.Numerics.Tests.ComplexTests.VerifyLogWithMultiply C# (CSharp) Method

        private static void VerifyLogWithMultiply(Complex complex1, Complex complex2)
        {
            // Log(complex1 * complex2) == Log(complex1) + Log(complex2), if -PI < Arctan(complex1) + Arctan(complex2) <= PI
            double equalityCondition = Math.Atan2(complex1.Imaginary, complex1.Real) + Math.Atan2(complex2.Imaginary, complex2.Real);
            if (equalityCondition <= -Math.PI || equalityCondition > Math.PI)
            {
                return;
            }

            Complex logComplex = Complex.Log(complex1 * complex2);
            Complex expected = Complex.Log(complex1) + Complex.Log(complex2);
            VerifyRealImaginaryProperties(logComplex, expected.Real, expected.Imaginary);
        }