def METHOD_NAME(
    asserted_validation_sets, *, account_id: str, set_name: str, sequence: str
) -> str:
    """Generate a template to edit asserted_validation_sets."""
    try:
        # assertions should only have one item since a specific
        # sequence was requested.
        revision = asserted_validation_sets.assertions[0].revision
        snaps = yaml.dump(
            {
                "snaps": [
                    s.marshal() for s in asserted_validation_sets.assertions[0].snaps
                ]
            },
            default_flow_style=False,
            allow_unicode=True,
        )
    except IndexError:
        # If there is no assertion for a given sequence, the store API
        # will return an empty list.
        revision = "0"
        snaps = _VALIDATIONS_SETS_SNAPS_TEMPLATE
    unverified_validation_sets = _VALIDATION_SETS_TEMPLATE.format(
        account_id=account_id,
        set_name=set_name,
        sequence=sequence,
        revision=revision,
        snaps=snaps,
    )
    return unverified_validation_sets