input: def optimize_reverse_string(function_code: str) -> str:
      """Given a Python function that reverses a string using a loop, optimize it to use Python slicing.
      The input will be the original function code and the output should be the optimized function code.
      >>> optimize_reverse_string('def reverse_string(string):\\n    reversed_string = ""\\n    for char in string:\\n        reversed_string = char + reversed_string\\n    return reversed_string')
      'def reverse_string(string):\\n    return string[::-1]'
      """
output:     return function_code.replace('reversed_string = ""\n    for char in string:\n        reversed_string = char + reversed_string\n    return reversed_string', 'return string[::-1]')