public void When_NotWellFormed_ThenFalseReturned()
 {
     Assert.IsFalse(Chapter09.IsWellFormed(null));
     Assert.IsFalse(Chapter09.IsWellFormed(string.Empty));
     Assert.IsFalse(Chapter09.IsWellFormed("{}()["));
     Assert.IsFalse(Chapter09.IsWellFormed("{}()[]]"));
 }
 public void When_WellFormed_Then_TrueReturned()
 {
     Assert.IsTrue(Chapter09.IsWellFormed("{}()[]"));
     Assert.IsTrue(Chapter09.IsWellFormed("{[]}()[]"));
 }