code: def get_paired_bams(align_bams, items):
      
      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)
docs: 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.