code: def __init__(self, logical_operator):
      super(Concat, self).__init__(logical_operator, transformer=True)
  
file_path: hummingbird/hummingbird/ml/operator_converters/_pipeline_implementations.py
imports: import numpy
  from onnxconverter_common.registration import register_converter
  import torch
  from ._physical_operator import PhysicalOperator
label_desc: Use image node_id 1 to create a new Concat object from inherited base classes: PhysicalOperator, torch.nn with example: obj = Concat(logical_operator)