code: def allocate_tensor(self, swap_path, numel, aligned_numel):
      assert self.has_space(aligned_numel)
      assert not self.offset in self.swap_tensors
  
      allocate_offset = self.offset
      swap_tensor = self.buffer.narrow(
          0, allocate_offset, aligned_numel
      )
      dest_tensor = swap_tensor.narrow(0, 0, numel)
  
      self.swap_tensors[allocate_offset] = swap_tensor
      self.compute_tensors[allocate_offset] = dest_tensor
      self.swap_paths[allocate_offset] = swap_path
      self.offset += aligned_numel
      self.num_elem += numel
  
      return (
          self.swap_tensors[allocate_offset],
          self.compute_tensors[allocate_offset],
      )
  
imports: import torch
  from deepspeed.utils.logging import logger
  from deepspeed import comm
label_desc: Use image node_id 4 for calling the SwapBuffer obj's underlying member method code with example usage: obj.allocate_tensor(swap_path, numel, aligned_numel) and returns: self,  self