docs: def load_db(self):
          """Load the taxonomy into a sqlite3 database.
  
          This will set ``self.db`` to a sqlite3 database which contains all of
          the taxonomic information in the reference package.
          """
  
          db = taxdb.Taxdb()
          db.create_tables()
          reader = csv.DictReader(self.open_resource('taxonomy', 'rU'))
          db.insert_from_taxtable(lambda: reader._fieldnames, reader)
  
          curs = db.cursor()
          reader = csv.DictReader(self.open_resource('seq_info', 'rU'))
          curs.executemany("INSERT INTO sequences VALUES (?, ?)",
                           ((row['seqname'], row['tax_id']) for row in reader))
  
          db.commit()
          self.db = db