code: def max_normal_germline_depth(in_file, params, somatic_info):
      
      bcf_in = pysam.VariantFile(in_file)
      depths = []
      for rec in bcf_in:
          stats = _is_possible_loh(rec, bcf_in, params, somatic_info)
          if tz.get_in(["normal", "depth"], stats):
              depths.append(tz.get_in(["normal", "depth"], stats))
      if depths:
          return np.median(depths) * NORMAL_FILTER_PARAMS["max_depth_percent"]
docs: Calculate threshold for excluding potential heterozygotes based on normal depth.