code: def test_call_git_items(temp_dir=None):
      # check proper handling of separator in call_git_items_
      repo, (hash1, hash2) = _create_test_gitrepo(temp_dir)
  
      expected_tree_lines = (
          f"100644 blob {hash1}\tfile1",
          f"100644 blob {hash2}\tfile2",
      )
  
      assert_equal(
          expected_tree_lines,
          tuple(repo.call_git_items_(["ls-tree", "HEAD"])),
      )
  
      assert_equal(
          expected_tree_lines,
          tuple(
              repo.call_git_items_(["ls-tree", "-z", "HEAD"], sep="\0")
          ),
      )
  
imports: import logging
  import os
  import os.path
  import sys
  from datalad.dataset.gitrepo import GitRepo, _get_dot_git
  from datalad.support.exceptions import CommandError, PathKnownToRepositoryError
  from datalad.tests.utils_pytest import SkipTest, assert_cwd_unchanged, assert_equal, assert_false, assert_in, assert_is_instance, assert_not_in, assert_raises, eq_, neq_, ok_, swallow_logs, with_tempfile, with_tree
  from datalad.utils import Path, chpwd
label_desc: Use image node_id 12 for calling a global function with example usage: test_call_git_items(temp_dir) without return types