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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 _check_for_problem_somatic_batches(items, config):
 """Identify problem batch setups for somatic calling. We do not support multiple tumors in a single batch and VarDict(Java) does not handle pooled calling, only tumor/normal. """

    to_check = []
    for data in items:
        data = copy.deepcopy(data)
        data["config"] = config_utils.update_w_custom(config, data)
        to_check.append(data)
    data_by_batches = collections.defaultdict(list)
    for data in to_check:
        batches = dd.get_batches(data)
        if batches:
            for batch in batches:
                data_by_batches[batch].append(data)
    for batch, items in data_by_batches.items():
        if vcfutils.get_paired(items):
            vcfutils.check_paired_problems(items)
        elif len(items) > 1:
            vcs = vcfutils.get_somatic_variantcallers(items)
            if "vardict" in vcs:
                raise ValueError("VarDict does not support pooled non-tumor/normal calling, in batch %s: %s"
                                 % (batch, [dd.get_sample_name(data) for data in items]))
            elif "mutect" in vcs or "mutect2" in vcs:
                raise ValueError("MuTect and MuTect2 require a 'phenotype: tumor' sample for calling, "
                                 "in batch %s: %s"
                                 % (batch, [dd.get_sample_name(data) for data in items]))