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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 load_variants(adapter, vcf_obj, case_obj, skip_case_id=False, gq_treshold=None, max_window=3000, variant_type='snv'):
 """Load variants for a family into the database. Args: adapter (loqusdb.plugins.Adapter):
 initialized plugin case_obj(Case):
 dict with case information nr_variants(int) skip_case_id (bool):
 whether to include the case id on variant level or not gq_treshold(int) max_window(int):
 Specify the max size for sv windows variant_type(str):
 'sv' or 'snv' Returns: nr_inserted(int) """

    if variant_type == 'snv':
        nr_variants = case_obj['nr_variants']
    else:
        nr_variants = case_obj['nr_sv_variants']

    nr_inserted = 0
    case_id = case_obj['case_id']
    if skip_case_id:
        case_id = None
    # Loop over the variants in the vcf
    with click.progressbar(vcf_obj, label="Inserting variants",length=nr_variants) as bar:

        variants = (build_variant(variant,case_obj,case_id, gq_treshold) for variant in bar)

    if variant_type == 'sv':
        for sv_variant in variants:
            if not sv_variant:
                continue
            adapter.add_structural_variant(variant=sv_variant, max_window=max_window)
            nr_inserted += 1

    if variant_type == 'snv':
        nr_inserted = adapter.add_variants(variants)

    LOG.info("Inserted %s variants of type %s", nr_inserted, variant_type)

    return nr_inserted