public void GetSum()
 {
   DoubleVector a = new DoubleVector(new double[4]{0,1,2,3});
   DoubleVector b = new DoubleVector(new double[4]{4,5,6,7});
   
   Assert.AreEqual(a.GetSum(),6);
   Assert.AreEqual(a.GetSum(),a.GetSumMagnitudes());
   
   Assert.AreEqual(b.GetSum(),22);
   Assert.AreEqual(b.GetSum(),b.GetSumMagnitudes());
 }