def METHOD_NAME(message: str) -> Dict[str, str]:
    """Extract extended metadata stored in the Git commit message.
    For example, a commit that looks like this::
        Do the thing!
        Piper-Changelog: 1234567
    Will return::
        {"Piper-Changelog": "1234567"}
    """
    metadata = {}
    for line in message.splitlines():
        if ":" not in line:
            continue
        key, value = line.split(":", 1)
        metadata[key] = value.strip()
    return metadata