code: def wrap_bos_eos(units, durations, f0, dense, bos, eos):
      assert units.size(0) == durations.size(0) == dense.size(0)
      if f0 is not None:
          assert units.size(0) == f0.size(0)
  
      units = torch.cat([bos, units, eos])
      z = torch.zeros_like(durations[0:1])
      durations = torch.cat([z, durations, z])
      if f0 is not None:
          z = torch.zeros_like(f0[0:1])
          f0 = torch.cat([z, f0, z])
      z = torch.zeros_like(dense[0:1, :])
      dense = torch.cat([z, dense, z])
  
      return units, durations, f0, dense
  
label_desc: Use image node_id 2 for calling a global function with example usage: wrap_bos_eos(units, durations, f0, dense, bos, eos) and returns: units,  durations,  f0,  dense