code: def detect_sv(align_bam, genome_build, dirs, config):
      
      work_dir = utils.safe_makedir(os.path.join(dirs["work"], "structural"))
      pair_stats = shared.calc_paired_insert_stats(align_bam)
      fix_bam = remove_nopairs(align_bam, work_dir, config)
      tier2_align = tiered_alignment(fix_bam, "2", True, [],
                                     genome_build, pair_stats,
                                     work_dir, dirs, config)
      if tier2_align:
          tier3_align = tiered_alignment(tier2_align, "3", "Ex 1100", ["-t", "300"],
                                         genome_build, pair_stats,
                                         work_dir, dirs, config)
          if tier3_align:
              hydra_bps = hydra_breakpoints(tier3_align, pair_stats)
docs: Detect structural variation from discordant aligned pairs.