public void EmptyStringTest()
{
// arrange
string str = String.Empty;
//act
SequenceBuilder sb = new SequenceBuilder();
//assert
Assert.Null(sb.CheckEven(str));
}
public void EvenIndexTest()
{
//arrange
string str = "ababab";
string result = "aaa";
//act
SequenceBuilder sb = new SequenceBuilder();
//assert
Assert.Equal(sb.CheckEven(str), result);
}