code: def _variant_eval_metrics(self, dup_bam):
          
          base, ext = os.path.splitext(dup_bam)
          end_strip = "-dup"
          base = base[:-len(end_strip)] if base.endswith(end_strip) else base
          mfiles = glob.glob("%s*eval_metrics" % base)
          if len(mfiles) > 0:
              with open(mfiles[0]) as in_handle:
                  # pull the metrics as JSON from the last line in the file
                  for line in in_handle:
                      pass
                  metrics = json.loads(line)
              return metrics
          else:
              return None
docs: Find metrics for evaluating variant effectiveness.