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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 _get_files_variantcall(sample):
 """Return output files for the variant calling pipeline. """

    out = []
    algorithm = sample["config"]["algorithm"]
    out = _maybe_add_summary(algorithm, sample, out)
    out = _maybe_add_alignment(algorithm, sample, out)
    out = _maybe_add_callable(sample, out)
    out = _maybe_add_disambiguate(algorithm, sample, out)
    out = _maybe_add_variant_file(algorithm, sample, out)
    out = _maybe_add_sv(algorithm, sample, out)
    out = _maybe_add_hla(algorithm, sample, out)
    out = _maybe_add_heterogeneity(algorithm, sample, out)

    out = _maybe_add_validate(algorithm, sample, out)
    return _add_meta(out, sample)