public void AddUser_NoError()
 {
     try
     {
         UserAccessor.AddUser("*****@*****.**", "password");
     }
     catch (InvalidOperationException e)
     {
         StringAssert.Contains(e.Message, "");
     }
     return;
 }
 public void AddUser_InvalidEmail()
 {
     try
     {
         UserAccessor.AddUser("test123 @gmail.com", "password");
     }
     catch (InvalidOperationException e)
     {
         StringAssert.Contains(e.Message, "");
         return;
     }
     Assert.Fail("The expected exception was not thrown.");
 }