code: def test_get_unique_invidx_low_mem():
      srcids = np.array([14, 0, 3, 3, 0, 3, 9, 5, 14, 12])
      dstids = np.array([10, 16, 12, 13, 10, 17, 16, 13, 14, 16])
      unique_nids = np.array([10, 11, 12, 13, 14, 15, 16, 17, 18, 19])
  
      uniques, idxes, srcids, dstids = _get_unique_invidx(
          srcids,
          dstids,
          unique_nids,
          low_mem=True,
      )
      expected_unqiues = np.array(
          [0, 3, 5, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19]
      )
      expected_idxes = np.array(
          [1, 2, 7, 6, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29]
      )
      expected_srcids = np.array([8, 0, 1, 1, 0, 1, 3, 2, 8, 6])
      expected_dstids = np.array([4, 10, 6, 7, 4, 11, 10, 7, 8, 10])
      assert np.all(
          uniques == expected_unqiues
      ), f"unique is not expected. {uniques} != {expected_unqiues}"
      assert np.all(
          idxes == expected_idxes
      ), f"indices is not expected. {idxes} != {expected_idxes}"
      assert np.all(
          srcids == expected_srcids
      ), f"srcids is not expected. {srcids} != {expected_srcids}"
      assert np.all(
          dstids == expected_dstids
      ), f"dstdis is not expected. {dstids} != {expected_dstids}"
  
file_path: dgl/tests/tools/test_convert_partition.py
imports: import os
  import tempfile
  import numpy
  import pytest
  import utils
  from convert_partition import _get_unique_invidx
label_desc: Use image node_id 3 for calling a global function with example usage: test_get_unique_invidx_low_mem() without return types