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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def delete(ctx, family_file, family_type, case_id):
 """Delete the variants of a case."""

    if not (family_file or case_id):
        LOG.error("Please provide a family file")
        ctx.abort()

    adapter = ctx.obj['adapter']

    # Get a ped_parser.Family object from family file
    family = None
    family_id = None
    if family_file:
        with open(family_file, 'r') as family_lines:
            family = get_case(
                family_lines=family_lines,
                family_type=family_type
            )
            family_id = family.family_id

    # There has to be a case_id or a family at this stage.
    case_id = case_id or family_id

    if not case_id:
        LOG.warning("Please provide a case id")
        ctx.abort()

    existing_case = adapter.case({'case_id': case_id})
    if not existing_case:
        LOG.warning("Case %s does not exist in database" %case_id)
        context.abort


    start_deleting = datetime.now()
    try:
        delete_command(
            adapter=adapter,
            case_obj=existing_case,
        )
    except (CaseError, IOError) as error:
        LOG.warning(error)
        ctx.abort()