code: def test_get_relative_url_use_directory_urls(self):
      to_files = [
          "index.md",
          "foo/index.md",
          "foo/bar/index.md",
          "foo/bar/baz/index.md",
          "foo.md",
          "foo/bar.md",
          "foo/bar/baz.md",
      ]
      to_file_urls = [
          "./",
          "foo/",
          "foo/bar/",
          "foo/bar/baz/",
          "foo/",
          "foo/bar/",
          "foo/bar/baz/",
      ]
  
      from_file = File(
          "img.jpg",
          "/path/to/docs",
          "/path/to/site",
          use_directory_urls=True,
      )
      self.assertEqual(from_file.url, "img.jpg")
  
      expected = [
          "img.jpg",  # img.jpg relative to .
          "../img.jpg",  # img.jpg relative to foo/
          "../../img.jpg",  # img.jpg relative to foo/bar/
          "../../../img.jpg",  # img.jpg relative to foo/bar/baz/
          "../img.jpg",  # img.jpg relative to foo
          "../../img.jpg",  # img.jpg relative to foo/bar
          "../../../img.jpg",  # img.jpg relative to foo/bar/baz
      ]
      for i, filename in enumerate(to_files):
          file = File(
              filename,
              "/path/to/docs",
              "/path/to/site",
              use_directory_urls=True,
          )
          self.assertEqual(file.url, to_file_urls[i])
          self.assertEqual(
              from_file.url_relative_to(file.url), expected[i]
          )
          self.assertEqual(from_file.url_relative_to(file), expected[i])
  
      from_file = File(
          "foo/img.jpg",
          "/path/to/docs",
          "/path/to/site",
          use_directory_urls=True,
      )
      self.assertEqual(from_file.url, "foo/img.jpg")
  
      expected = [
          "foo/img.jpg",  # foo/img.jpg relative to .
          "img.jpg",  # foo/img.jpg relative to foo/
          "../img.jpg",  # foo/img.jpg relative to foo/bar/
          "../../img.jpg",  # foo/img.jpg relative to foo/bar/baz/
          "img.jpg",  # foo/img.jpg relative to foo
          "../img.jpg",  # foo/img.jpg relative to foo/bar
          "../../img.jpg",  # foo/img.jpg relative to foo/bar/baz
      ]
      for i, filename in enumerate(to_files):
          file = File(
              filename,
              "/path/to/docs",
              "/path/to/site",
              use_directory_urls=True,
          )
          self.assertEqual(file.url, to_file_urls[i])
          self.assertEqual(
              from_file.url_relative_to(file.url), expected[i]
          )
          self.assertEqual(from_file.url_relative_to(file), expected[i])
  
      from_file = File(
          "index.html",
          "/path/to/docs",
          "/path/to/site",
          use_directory_urls=True,
      )
      self.assertEqual(from_file.url, "./")
  
      expected = [
          "./",  # . relative to .
          "../",  # . relative to foo/
          "../../",  # . relative to foo/bar/
          "../../../",  # . relative to foo/bar/baz/
          "../",  # . relative to foo
          "../../",  # . relative to foo/bar
          "../../../",  # . relative to foo/bar/baz
      ]
      for i, filename in enumerate(to_files):
          file = File(
              filename,
              "/path/to/docs",
              "/path/to/site",
              use_directory_urls=True,
          )
          self.assertEqual(file.url, to_file_urls[i])
          self.assertEqual(
              from_file.url_relative_to(file.url), expected[i]
          )
          self.assertEqual(from_file.url_relative_to(file), expected[i])
  
      from_file = File(
          "file.md",
          "/path/to/docs",
          "/path/to/site",
          use_directory_urls=True,
      )
      self.assertEqual(from_file.url, "file/")
  
      expected = [
          "file/",  # file relative to .
          "../file/",  # file relative to foo/
          "../../file/",  # file relative to foo/bar/
          "../../../file/",  # file relative to foo/bar/baz/
          "../file/",  # file relative to foo
          "../../file/",  # file relative to foo/bar
          "../../../file/",  # file relative to foo/bar/baz
      ]
      for i, filename in enumerate(to_files):
          file = File(
              filename,
              "/path/to/docs",
              "/path/to/site",
              use_directory_urls=True,
          )
          self.assertEqual(file.url, to_file_urls[i])
          self.assertEqual(
              from_file.url_relative_to(file.url), expected[i]
          )
          self.assertEqual(from_file.url_relative_to(file), expected[i])
  
imports: import os
  import sys
  import unittest
  from unittest import mock
  from mkdocs.structure.files import File, Files, _sort_files, get_files
  from mkdocs.tests.base import PathAssertionMixin, load_config, tempdir
label_desc: Use image node_id 16 for calling the TestFiles obj's underlying member method code with example usage: obj.test_get_relative_url_use_directory_urls() without return types