class_docstr: Inserted between layers with different packing factors.
class_docstr_tok: ["Inserted","between","layers","with","different","packing","factors","."]
code: def initialize(self):
      shape = self.attributes["target_shape"]
      if shape[0] is None:
          shape = shape[1:]
      dims = [
          f"N_SIZE_{i}_{self.index}" for i in range(1, len(shape) + 1)
      ]
  
      self.add_output_variable(shape, dims)
  
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 1 for calling the Repack obj's underlying member method code with example usage: obj.initialize() without return types