docstr: ...Test HawkesSumExpKern setting of step parameter
  of solver
docstr_tok: ["...","Test","HawkesSumExpKern","setting","of","step","parameter","of","solver"]
code: def test_HawkesSumExpKern_solver_step(self):
      """...Test HawkesSumExpKern setting of step parameter
      of solver
      """
      for solver in solvers:
          if solver in ["bfgs"]:
              msg = '^Solver "%s" has no settable step$' % solver
              with self.assertWarnsRegex(RuntimeWarning, msg):
                  learner = HawkesSumExpKern(
                      self.decays,
                      solver=solver,
                      step=1,
                      **Test.specific_solver_kwargs(solver),
                  )
                  self.assertIsNone(learner.step)
          else:
              learner = HawkesSumExpKern(
                  self.decays,
                  solver=solver,
                  step=self.float_1,
                  **Test.specific_solver_kwargs(solver),
              )
              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)
  
          if solver in ["sgd"]:
              msg = "^SGD step needs to be tuned manually$"
              with self.assertWarnsRegex(RuntimeWarning, msg):
                  learner = HawkesSumExpKern(
                      self.decays, solver="sgd", max_iter=1
                  )
                  learner.fit(self.events, 0.3)
  
imports: import unittest
  import numpy
  from tick.base.inference import InferenceTest
  from tick.hawkes import SimuHawkesSumExpKernels, SimuHawkesMulti
  from tick.hawkes.inference import HawkesSumExpKern
  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 15 for calling the Test obj's underlying member method code with example usage: obj.test_HawkesSumExpKern_solver_step() without return types