new_contents: import unittest
  import numpy as np
  
  from pax import core, plugin
  from pax.datastructure import Event, Peak
  from pax.utils import empty_event
  
  
  class TestPosRecChiSquareGamma(unittest.TestCase):
  
      def setUp(self):
          self.pax = core.Processor(config_names='posrecChi',
                                    just_testing=True,
                                    config_dict={'pax': {'plugin_group_names':
                                                 ['test'], 'test':
                                                 'PosRecChiSquareGamma.PosRecChiSquareGamma'}})
          self.plugin = self.pax.get_plugin_by_name('PosRecChiSquareGamma')
  
          self.e = empty_event()
  
      def example_event(self, channels_with_something):
          channels = np.array(channels_with_something, dtype='float64')
          e = empty_event()
          e.peaks.append(Peak({'left':  5,
                               'right': 9,
                               'type':  'S2',
                               'detector':  'tpc',
                               'area_per_channel': channels}))
          return e
  
      def test_get_chisquare_plugin(self):
          self.assertIsInstance(self.plugin, plugin.TransformPlugin)
          self.assertEqual(self.plugin.__class__.__name__, 'PosRecChiSquareGamma')
  
      def test_posrec(self):
          e = self.example_event([0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0,
                                  0, 1, 1, 0, 0, 3, 6, 7, 2, 2, 0, 0, 0, 0, 0,
                                  1, 1, 0, 0, 0, 0, 0, 1, 2, 0, 0, 0, 1, 2, 2,
                                  3, 2, 14, 33, 12, 5, 2, 2, 0, 1, 0, 0, 1, 1,
                                  0, 1, 0, 0, 0, 0, 0, 0, 5, 40, 226, 45, 7, 0,
                                  2, 1, 1, 0, 1, 0, 0, 0, 1, 0, 7, 14, 36, 3, 0,
                                  2, 1, 0, 0, 0, 1, 4, 4, 3, 1, 0])
          e = self.plugin.transform_event(e)
          self.assertIsInstance(e, Event)
          self.assertEqual(len(e.peaks), 1)
          self.assertEqual(len(e.S2s()), 1)
          self.assertEqual(len(e.peaks[0].reconstructed_positions), 1)
          rp = e.peaks[0].reconstructed_positions[0]
          self.assertEqual(rp.algorithm, 'PosRecChiSquareGamma')
          # position agrees within one cm for test
          x_truth = 3.1625
          y_truth = -10.0172
          self.assertTrue(rp.x < x_truth+1 and rp.x > x_truth-1)
          self.assertTrue(rp.y < y_truth+1 and rp.y > y_truth-1)
  
  
  if __name__ == '__main__':
      unittest.main()
  
subject: Add test for PosRecChiSquareGamma