code: def is_html_document():
      any_whitespace = r"[\s]*"
      anything = r"[\s\S\d\D\w\W]*"
      regexp = (
          rf'^{any_whitespace}({anything})<html( lang="en")*>{any_whitespace}'
          rf"<head>({anything})<\/head>{any_whitespace}"
          rf"<body({anything})>({anything})<\/body>{any_whitespace}"
          rf"<\/html>{any_whitespace}$"
      )
      return all_of(instance_of(str), matches_regexp(regexp))
  
imports: import contextlib
  import io
  import pathlib
  import typing
  from unittest.mock import Mock, patch
  import jsonpickle
  import pandas
  import plotly.express
  import plotly.io
  from hamcrest import all_of, any_of, assert_that, calling, equal_to, greater_than, has_entries, has_length, instance_of, is_, matches_regexp, only_contains, raises
  from ipywidgets import VBox, Widget
  from deepchecks.core.check_result import CheckFailure, CheckResult
  from deepchecks.core.errors import DeepchecksValueError
  from deepchecks.tabular.checks import ColumnsInfo, MixedNulls
  from deepchecks.utils.json_utils import from_json
  from tests.common import DummyCheck, create_check_result, create_suite_result, instance_of_ipython_formatter
label_desc: Use image node_id 47 for calling a global function with example usage: is_html_document() and returns: all_of