code: def densify(t):
      """Removes holes in an array.
  
      This function converts a 1-dimensional tensor of length n without duplicates
      to a 1-dimensional tensor of the same length with all elements less than n
      while preserving the order. For example,
  
          [1, 0, 4, 5, 10, 9] -> [1, 0, 2, 3, 5, 4]
      """
      _, sorted_indices = torch.sort(t)
      _, dense_t = torch.sort(sorted_indices)
      return dense_t
  
imports: import argparse
  import ast
  import os
  import signal
  import threading
  import time
  from typing import Dict, List, Optional, Union
  import torch
  from fairseq import distributed_utils, tasks, utils
  from pytorch_translate.file_io import PathManager
label_desc: Use image node_id 3 for calling a global function with example usage: densify(t) and returns: dense_t