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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 annotate(ctx, variant_file, sv):
 """Annotate the variants in a VCF """

    adapter = ctx.obj['adapter']

    variant_path = os.path.abspath(variant_file)

    expected_type = 'snv'
    if sv:
        expected_type = 'sv'

    if 'sv':
        nr_cases = adapter.nr_cases(sv_cases=True)
    else:
        nr_cases = adapter.nr_cases(snv_cases=True)
    LOG.info("Found {0} {1} cases in database".format(nr_cases, expected_type))

    vcf_obj = get_file_handle(variant_path)
    add_headers(vcf_obj, nr_cases=nr_cases, sv=sv)
    # Print the headers
    for header_line in vcf_obj.raw_header.split('\n'):
        if len(header_line) == 0:
            continue
        click.echo(header_line)

    start_inserting = datetime.now()
    
    if sv:
        annotated_variants = annotate_svs(adapter, vcf_obj)
    else:
        annotated_variants = annotate_snvs(adapter, vcf_obj)
    # try:
    for variant in annotated_variants:
        click.echo(str(variant).rstrip())