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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 _combine_qc_samples(samples):
 """Combine split QC analyses into single samples based on BAM files. """

    by_bam = collections.defaultdict(list)
    for data in [utils.to_single_data(x) for x in samples]:
        batch = dd.get_batch(data) or dd.get_sample_name(data)
        if not isinstance(batch, (list, tuple)):
            batch = [batch]
        batch = tuple(batch)
        by_bam[(dd.get_align_bam(data) or dd.get_work_bam(data), batch)].append(data)
    out = []
    for data_group in by_bam.values():
        data = data_group[0]
        alg_qc = []
        qc = {}
        metrics = {}
        for d in data_group:
            qc.update(dd.get_summary_qc(d))
            metrics.update(dd.get_summary_metrics(d))
            alg_qc.extend(dd.get_algorithm_qc(d))
        data["config"]["algorithm"]["qc"] = alg_qc
        data["summary"]["qc"] = qc
        data["summary"]["metrics"] = metrics
        out.append([data])
    return out