code: def forward_chainer(self, inputs):
      c1, c2, x1, x2 = inputs
      out = chainer.functions.slstm(c1, c2, x1, x2)
      return out
  
imports: import random
  import chainer
  import numpy
  import chainerx
  from chainer import utils
  from chainerx_tests import array_utils
  from chainerx_tests import dtype_utils
  from chainerx_tests import op_utils
label_desc: Use image node_id 4 for calling the TestSLstm obj's underlying member method code with example usage: obj.forward_chainer(inputs) and returns: out