The Brackets Problem

You’re given a string that may contain the characters {, }, [, ], (, and ).

Task: Verify that the string is balanced. A balanced string is one where every opening character, {, [, or (, has a corresponding closing character, }, ], or ).

Write a function called is_balanced(string: str) -> bool which verifies the balance of a string.

Example:

is_balanced('(())[]{}') -> True

is_balanced('{([(){}])()}') -> True

is_balanced('{}[]())') -> False