docs: def load_alleles_dict():
      """Create a dictionary mapping each unique allele name to a namedtuple
      containing information about that alleles class, locus, species, &c.
      """
      alleles = load_alleles()
      result = {}
      for allele in alleles:
          for name in {allele.name}.union(allele.synonyms):
              result[name] = allele
      return result