code: def format(self, node):
      params = self._default_function_params(node)
      params["weights"] = "w{0}, wr{0}, b{0}".format(str(node.index))
      return self.template.format(**params)
  
imports: from hls4ml.backends.backend import get_backend
  from hls4ml.backends.template import FunctionCallTemplate, LayerConfigTemplate
  from hls4ml.model.layers import GRU, LSTM, SimpleRNN
label_desc: Use image node_id 2 for calling the SimpleRNNFunctionTemplate obj's underlying member method code with example usage: obj.format(node) and returns: self