private void testContains(BasicStack <DSString> the_stack)
{
//make sure all items are matched inside
Assert.AreEqual(true, the_stack.contains(new DSString("0")));
Assert.AreEqual(true, the_stack.contains(new DSString("1")));
Assert.AreEqual(true, the_stack.contains(new DSString("2")));
Assert.AreEqual(true, the_stack.contains(new DSString("3")));
Assert.AreEqual(true, the_stack.contains(new DSString("4")));
Assert.AreEqual(true, the_stack.contains(new DSString("5")));
Assert.AreEqual(true, the_stack.contains(new DSString("6")));
Assert.AreEqual(true, the_stack.contains(new DSString("7")));
Assert.AreEqual(true, the_stack.contains(new DSString("8")));
Assert.AreEqual(true, the_stack.contains(new DSString("9")));
//check after removal
the_stack.pop();
Assert.AreEqual(false, the_stack.contains(new DSString("9")));
//check after adding
the_stack.push(new DSString("13"));
Assert.AreEqual(true, the_stack.contains(new DSString("13")));
//check after removing all
the_stack.clear();
Assert.AreEqual(false, the_stack.contains(new DSString("13")));
Assert.AreEqual(false, the_stack.contains(new DSString("0")));
Assert.AreEqual(false, the_stack.contains(new DSString("1")));
Assert.AreEqual(false, the_stack.contains(new DSString("2")));
Assert.AreEqual(false, the_stack.contains(new DSString("3")));
Assert.AreEqual(false, the_stack.contains(new DSString("4")));
Assert.AreEqual(false, the_stack.contains(new DSString("5")));
Assert.AreEqual(false, the_stack.contains(new DSString("6")));
Assert.AreEqual(false, the_stack.contains(new DSString("7")));
Assert.AreEqual(false, the_stack.contains(new DSString("8")));
Assert.AreEqual(false, the_stack.contains(new DSString("9")));
}