code: def _set_state_impl(self, key, param):
      self.m[key] = np.zeros_like(param)
      self.v[key] = np.zeros_like(param)
      self.v_hat[key] = np.zeros_like(param)
      self.t[key] = 0
  
file_path: nnabla/python/test/solver/test_amsbound.py
imports: import pytest
  import nnabla.solvers
  import numpy
  from solver_test_utils import solver_tester, RefSolver
  from nbla_test_utils import list_context
label_desc: Use image node_id 2 for calling the RefAMSBound obj's underlying member method code with example usage: obj._set_state_impl(key, param) without return types