You're working with an intern that keeps coming to you with some code that won't run because the braces, brackets, and parentheses are off. To save you both some time, you decide to write a braces/brackets/parentheses validator.
Let's say that:
(,{, and[are called "openers", and),}, and]are called "closers".
Write an efficient method that tells us whether or not an input string's openers and closers are properly nested.