docstr: ...Test that loss is still consistent after decays modification in
  ModelHawkesSumExpKernLeastSq
docstr_tok: ["...","Test","that","loss","is","still","consistent","after","decays","modification","in","ModelHawkesSumExpKernLeastSq"]
code: def test_model_hawkes_least_sq_change_decays(self):
      """...Test that loss is still consistent after decays modification in
      ModelHawkesSumExpKernLeastSq
      """
      decays = np.random.rand(self.n_decays)
  
      self.assertNotEqual(decays[0], self.decays[0])
  
      model_change_decay = ModelHawkesSumExpKernLeastSq(decays=decays)
      model_change_decay.fit(self.timestamps_list)
      loss_old_decay = model_change_decay.loss(self.coeffs)
  
      model_change_decay.decays = self.decays
  
      self.assertNotEqual(
          loss_old_decay, model_change_decay.loss(self.coeffs)
      )
  
      self.assertEqual(
          self.model_list.loss(self.coeffs),
          model_change_decay.loss(self.coeffs),
      )
  
imports: import pickle
  import unittest
  import numpy
  from numpy.linalg import norm
  from scipy.optimize import check_grad, fmin_bfgs
  from tick.base.inference import InferenceTest
  from tick.hawkes.model import ModelHawkesSumExpKernLeastSq
  from tick.hawkes.model.tests.model_hawkes_test_utils import hawkes_sumexp_kernel_intensities, hawkes_sumexp_kernel_varying_intensities, hawkes_least_square_error
label_desc: Use image node_id 9 for calling the Test obj's underlying member method code with example usage: obj.test_model_hawkes_least_sq_change_decays() without return types