  class TestStackMin(object):
  
      def test_stack_min(self):
          print('Test: Push on empty stack, non-empty stack')
          stack = MyStack()
          stack.push(5)
          assert_equal(stack.peek(), 5)
          assert_equal(stack.min(), 5)
          stack.push(1)
          assert_equal(stack.peek(), 1)
 
</s> remove     "        stack = MyStack()\n",
 </s> add     "        stack = StackMin()\n", </s> remove     "        stack = MyStack()\n",
 </s> add     "        stack = StackMin()\n", </s> remove     "* If we call this function on an empty stack, can we return maxsize?\n",
 </s> add     "* Can we assume the input values for push are valid?\n",
    "    * Yes\n",
    "* If we call this function on an empty stack, can we return sys.maxsize?\n",
        stack = StackMin()
  class TestStackMin(object):
  
      def test_stack_min(self):
          print('Test: Push on empty stack, non-empty stack')
        stack = StackMin()
          stack.push(5)
          assert_equal(stack.peek(), 5)
          assert_equal(stack.min(), 5)
          stack.push(1)
          assert_equal(stack.peek(), 1)
keep keep keep keep replace keep keep keep keep keep
 Polish stack min challenge and solution (#72)

Update constraints, algorithm discussion, code, and tests. 
stacks_queues/stack_min/test_stack_min.py