public void GetIndexes_WhenSubstringNotPresent_ReturnsEmptyCollection()
 {
     var sut = new PatternMatcher("abra kadabra");
     Assert.AreEqual(0, sut.GetIndexes("z").Count);
 }
 public void GetIndexes_WhenGivenNullSubstring_ThrowsArgumentNullException()
 {
     var sut = new PatternMatcher("abra kadabra");
     Assert.Throws<ArgumentNullException>(() => sut.GetIndexes(null));
 }