docstr: ...Test LogisticRegression setting of step parameter of solver
          
docstr_tok: ["...","Test","LogisticRegression","setting","of","step","parameter","of","solver"]
code: def test_PoissonRegression_solver_step(self):
      """...Test LogisticRegression setting of step parameter of solver"""
      for solver in PoissonRegression._solvers.keys():
          if solver == "bfgs":
              learner = PoissonRegression(solver=solver)
              self.assertIsNone(learner.step)
              learner = PoissonRegression(
                  solver=solver, step=self.float_1
              )
              self.assertIsNone(learner.step)
              msg = '^Solver "bfgs" has no settable step$'
              with self.assertWarnsRegex(RuntimeWarning, msg):
                  learner.step = self.float_2
                  self.assertIsNone(learner.step)
          else:
              learner = PoissonRegression(
                  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)
  
imports: import unittest
  from itertools import product
  import numpy
  from tick.base.inference import InferenceTest
  from tick.linear_model import SimuPoisReg, PoissonRegression
  from tick.simulation import weights_sparse_gauss
label_desc: Use image node_id 10 for calling the Test obj's underlying member method code with example usage: obj.test_PoissonRegression_solver_step() without return types