def METHOD_NAME(lines: Sequence[str], spaces: int = 1) -> str:
    """
    Indent code block.
    :param lines:
    :type lines: str
    :param spaces: times of four
    :return:
    """
    string_io = StringIO(str(lines))
    indentation = spaces * 4
    prefix = " " * indentation
    lines = []
    for line in string_io:
        if line != "\n":
            line = prefix + line
        lines.append(line)
    return "".join(lines)