code: def _get_impact_info(vcf_reader):
      
      ImpactInfo = collections.namedtuple("ImpactInfo", "header, gclass, id")
      KEY_2_CLASS = {
          'CSQ': geneimpacts.VEP,
          'ANN': geneimpacts.SnpEff,
          'BCSQ': geneimpacts.BCFT}
      for l in (x.strip() for x in _from_bytes(vcf_reader.raw_header).split("\n")):
          if l.startswith("##INFO"):
              patt = re.compile("(\w+)=(\"[^\"]+\"|[^,]+)")
              stub = l.split("=<")[1].rstrip(">")
              d = dict(patt.findall(_from_bytes(stub)))
              if d["ID"] in KEY_2_CLASS:
                  return ImpactInfo(_parse_impact_header(d), KEY_2_CLASS[d["ID"]], d["ID"])
docs: Retrieve impact parsing information from INFO header.