code: def to_dict(self):
          
          return dict(
              contig=self.original_contig,
              start=self.original_start,
              ref=self.original_ref,
              alt=self.original_alt,
              ensembl=self.ensembl,
              allow_extended_nucleotides=self.allow_extended_nucleotides,
              normalize_contig_name=self.normalize_contig_name)
docs: We want the original values (un-normalized) field values while
          serializing since normalization will happen in __init__.