new_contents: import os
  import unittest
  
  from rmgpy import settings
  from rmgpy.data.rmg import RMGDatabase
  
  import afm.react
  import afm.fragment
  
  TESTFAMILY = 'R_Recombination'
  
  class TestReact(unittest.TestCase):
  
      def setUp(self):
          """
          A function run before each unit test in this class.
          """
  
          # load kinetics database
          db_path = settings['database.directory']
          self.database = RMGDatabase()
  
          # forbidden structure loading
          self.database.loadForbiddenStructures(os.path.join(db_path, 'forbiddenStructures.py'))
          # kinetics family loading
          self.database.loadKinetics(os.path.join(db_path, 'kinetics'),
                                     kineticsFamilies=[TESTFAMILY],
                                     reactionLibraries=[]
                                     )
  
      def test_react_fragments1(self):
          
          frag1 = afm.fragment.Fragment(label='frag1').from_SMILES_like_string('c1ccccc1CCCR')
          fragment_tuple = (frag1, )
          reactions = afm.react.react_fragments(self.database.kinetics, 
                                                fragment_tuple,
                                                only_families=[TESTFAMILY],
                                                prod_resonance=False)
  
          self.assertTrue(len(reactions)==28) 
subject: add a unittest for react_fragments()