Split aligned bams into tumor / normal pairs if this is a paired analysis.
    Allows cases with only tumor BAMs to handle callers that can work without
    normal BAMs or with normal VCF panels.

def get_paired_bams(align_bams, items):
    """Split aligned bams into tumor / normal pairs if this is a paired analysis.
    Allows cases with only tumor BAMs to handle callers that can work without
    normal BAMs or with normal VCF panels.
    """
    tumor_bam, tumor_name, normal_bam, normal_name, normal_panel, tumor_config, normal_data = (None,) * 7
    for bamfile, item in zip(align_bams, items):
        phenotype = get_paired_phenotype(item)
        if phenotype == "normal":
            normal_bam = bamfile
            normal_name = dd.get_sample_name(item)
            normal_data = item
        elif phenotype == "tumor":
            tumor_bam = bamfile
            tumor_name = dd.get_sample_name(item)
            tumor_data = item
            tumor_config = item["config"]
            normal_panel = dd.get_background_variant(item)
    if tumor_bam or tumor_name:
        return PairedData(tumor_bam, tumor_name, normal_bam,
                          normal_name, normal_panel, tumor_config,
                          tumor_data, normal_data)