from typing import Optional


def parse_suffixed_line(line: str, suffix: Optional[str]) -> Optional[str]:
    """
    Return a `line` without `suffix` if `line` starts with `suffix`, else return `None`.
    """
    if suffix is None:
        return None

    suffix = suffix.rstrip()

    if line.endswith(suffix):
        return line.removesuffix(suffix)

    if line == suffix:
        return ""

    return None