docs: def bonds(lines, atoms):
      """Parse bond block into bond objects
  
      Returns:
          dict: networkx adjacency dict
      """
      # Convert sdf style stereobond (see chem.model.bond.Bond)
      conv_stereo_table = {0: 0, 1: 1, 3: 3, 4: 3, 6: 2}
      results = {a: {} for a in atoms}
      for line in lines:
          bond = Bond()
          first = int(line[0:3])
          second = int(line[3:6])
          if first > second:
              bond.is_lower_first = 0
          order = int(line[6:9])
          if order < 4:
              bond.order = order
          bond.type = conv_stereo_table[int(line[9:12])]
          results[first][second] = {"bond": bond}
          results[second][first] = {"bond": bond}
      return results