def is_palindrome(string: str) -> bool:
    """Checks is given string is palindrome.

    Examples:
        >>> assert is_palindrome("abccba")
        >>>
        >>> assert is_palindrome("123321")
        >>>
        >>> assert not is_palindrome("abccbX")
    """
    if not isinstance(string, str):
        raise TypeError("Input value should be string.")
    return string.lower() == string[::-1].lower()