code: def create_tumor_bamdir(tumor, tumor_bam, normal_bam, work_dir):
      
      bam_dir = utils.safe_makedir(os.path.join(work_dir, tumor, "in_bams"))
      normal_bam_ready = os.path.join(bam_dir, os.path.basename(normal_bam))
      utils.symlink_plus(normal_bam, normal_bam_ready)
      tumor_bam_ready = os.path.join(bam_dir, os.path.basename(tumor_bam))
      utils.symlink_plus(tumor_bam, tumor_bam_ready)
      return bam_dir, normal_bam_ready
docs: Create expected input directory with tumor/normal BAMs in one place.