docstr: ...Test CoxRegression setting of step parameter of solver
          
docstr_tok: ["...","Test","CoxRegression","setting","of","step","parameter","of","solver"]
code: def test_CoxRegression_solver_step(self):
      """...Test CoxRegression setting of step parameter of solver"""
      for solver in self.solvers:
          learner = CoxRegression(solver=solver, step=self.float_1)
          self.assertEqual(learner.step, self.float_1)
          self.assertEqual(learner._solver_obj.step, self.float_1)
          learner.step = self.float_2
          self.assertEqual(learner.step, self.float_2)
          self.assertEqual(learner._solver_obj.step, self.float_2)
  
file_path: tick/tick/survival/tests/cox_regression_test.py
imports: import unittest
  import numpy
  from tick.base.inference import InferenceTest
  from tick.survival import SimuCoxReg, CoxRegression
  from tick.simulation import weights_sparse_gauss
  from tick.preprocessing.features_binarizer import FeaturesBinarizer
  from tick.prox import ProxZero, ProxL1, ProxL2Sq, ProxElasticNet, ProxTV, ProxBinarsity
  from tick.solver import GD, AGD
label_desc: Use image node_id 8 for calling the Test obj's underlying member method code with example usage: obj.test_CoxRegression_solver_step() without return types