code: def _pad_sequence_fix(attr, kernel_dim=None):
      
      new_attr = ()
      if len(attr) % 2 == 0:
          for index in range(int(len(attr) / 2)):
              new_attr = new_attr + attr[index::int(len(attr) / 2)]
          # Making sure pad values  are in the attr for all axes.
          if kernel_dim is not None:
              while len(new_attr) < kernel_dim*2:
                  new_attr = new_attr + (0, 0)
  
      return new_attr
docs: Changing onnx's pads sequence to match with mxnet's pad_width
      mxnet: (x1_begin, x1_end, ... , xn_begin, xn_end)
      onnx: (x1_begin, x2_begin, ... , xn_end, xn_end)