docstr: ...Test HawkesExpKern starting point of fit method
          
docstr_tok: ["...","Test","HawkesExpKern","starting","point","of","fit","method"]
code: def test_HawkesExpKern_fit_start(self):
      """...Test HawkesExpKern starting point of fit method"""
      n_nodes = len(self.events)
      n_coefs = n_nodes + n_nodes * n_nodes
      # Do not step
      learner = HawkesExpKern(self.decays, max_iter=-1)
  
      learner.fit(self.events)
      np.testing.assert_array_equal(learner.coeffs, np.ones(n_coefs))
  
      learner.fit(self.events, start=self.float_1)
      np.testing.assert_array_equal(
          learner.coeffs, np.ones(n_coefs) * self.float_1
      )
  
      learner.fit(self.events, start=self.int_1)
      np.testing.assert_array_equal(
          learner.coeffs, np.ones(n_coefs) * self.int_1
      )
  
      random_coeffs = np.random.rand(n_coefs)
      learner.fit(self.events, start=random_coeffs)
      np.testing.assert_array_equal(learner.coeffs, random_coeffs)
  
imports: import unittest
  import numpy
  from tick.base.inference import InferenceTest
  from tick.hawkes import SimuHawkesExpKernels
  from tick.hawkes.inference import HawkesExpKern
  from tick.hawkes.model.model_hawkes_expkern_leastsq import ModelHawkesExpKernLeastSq
  from tick.hawkes.model.model_hawkes_expkern_loglik import ModelHawkesExpKernLogLik
  from tick.prox import ProxNuclear
  from tick.prox import ProxPositive, ProxL1, ProxL2Sq, ProxElasticNet
  from tick.solver import AGD, GD, BFGS, SGD, SVRG
label_desc: Use image node_id 5 for calling the Test obj's underlying member method code with example usage: obj.test_HawkesExpKern_fit_start() without return types