public void test3()
 {
     Assert.Equal(19.617, MediaPesata.Calcola("file3.txt"), 3);
 }
 public void test1()
 {
     Assert.Equal(6.962, MediaPesata.Calcola("file1.txt"), 3);
 }
 public void test2()
 {
     Assert.Equal(24.09, MediaPesata.Calcola("file2.txt"), 3);
 }