docs: def search_refdata(self, seq, locus):
          """
          This checks to see if a sequence already exists in the reference data. If it does, then it'll return the known annotation.
  
          :return: The Annotation of associated with the input sequence
          :rtype: :ref:`ann`
  
          Example:
  
              >>> from Bio.Seq import Seq
              >>> from seqann.models.reference_data import ReferenceData
              >>> sequence = Seq('AGAGACTCTCCCGAGGATTTCGTGTACCAGTTTAAGGCCATGTGCTACTTCACC')
              >>> refdata = ReferenceData()
              >>> matched_annotation = refdata.search_refdata(sequence, locus)
  
          """
          # TODO: ONLY MAKE ONE CONNECTION
          # TODO: add try statement
          # TODO: take password from environment variable
          if self.server_avail:
              hla, loc = locus.split('-')
              p1 = "SELECT ent.name "
              p2 = "FROM bioentry ent,biosequence seq,biodatabase dbb "
              p3 = "WHERE dbb.biodatabase_id = ent.biodatabase_id AND seq.bioentry_id = ent.bioentry_id "
              p4 = " AND dbb.name = \"" + self.dbversion + "_" + loc + "\""
              p5 = " AND seq.seq = \"" + str(seq.seq) + "\""
              select_stm = p1 + p2 + p3 + p4 + p5
  
              # TODO: add try statement
              conn = pymysql.connect(host=biosqlhost, port=biosqlport,
                                     user=biosqluser, passwd=biosqlpass,
                                     db=biosqldb)
              cur = conn.cursor()
              cur.execute(select_stm)
  
              typ = ''
              for row in cur:
                  typ = row[0]
  
              cur.close()
              conn.close()
  
              if typ:
                  if self.verbose:
                      self.logger.info("Exact typing found in BioSQL database")
                  seqrecord = self.seqrecord(typ, loc)
                  return self.seqannotation(seqrecord, typ, loc)
              else:
                  return
          else:
              if str(seq.seq) in self.seqref:
                  if self.verbose:
                      self.logger.info("Exact typing found in dat file")
                  seqrec = self.hlaref[self.seqref[str(seq.seq)]]
                  return self.seqannotation(seqrec,
                                            self.seqref[str(seq.seq)],
                                            locus)
              else:
                  return