def METHOD_NAME(file_, curr_version, new_version):
    """Read in contents of `file` and then update version.
    Implementation detail: replaces instances of `curr_version` with `new_version`
    using python3 str.replace().
    Args:
        file_ (str): the path to the file
        curr_version (str): the current version
        new_version (str): the version to bump to
    Raises:
        Exception: if contents before and after match.
    """
    with open(file_, "r") as f:
        contents = f.read()
    new_contents = contents.replace(str(curr_version), str(new_version))
    if contents == new_contents:
        raise Exception("Did not expect no changes")
    with open(file_, "w") as f:
        f.write(new_contents)