code: def format(self, node):
      params = self._default_function_params(node)
      params["size"] = np.prod(node.get_output_variable().shape)
  
      return self.template.format(**params)
  
file_path: hls4ml/hls4ml/backends/fpga/passes/repack_stream.py
imports: import numpy
  from hls4ml.backends.template import FunctionCallTemplate
  from hls4ml.model.layers import Layer, Reshape, register_layer
  from hls4ml.model.optimizer import OptimizerPass
label_desc: Use image node_id 2 for calling the RepackFunctionTemplate obj's underlying member method code with example usage: obj.format(node) and returns: self