code: def test_get_visual_block_feature_union():
      f_union = FeatureUnion([("pca", PCA()), ("svd", TruncatedSVD())])
      est_html_info = _get_visual_block(f_union)
      assert est_html_info.kind == "parallel"
      assert est_html_info.names == ("pca", "svd")
      assert est_html_info.estimators == tuple(
          trans[1] for trans in f_union.transformer_list
      )
      assert est_html_info.name_details == (None, None)
  
imports: import html
  import locale
  import re
  from contextlib import closing
  from io import StringIO
  from unittest.mock import patch
  import pytest
  from sklearn import config_context
  from sklearn.base import BaseEstimator
  from sklearn.cluster import AgglomerativeClustering, Birch
  from sklearn.compose import ColumnTransformer, make_column_transformer
  from sklearn.datasets import load_iris
  from sklearn.decomposition import PCA, TruncatedSVD
  from sklearn.ensemble import StackingClassifier, StackingRegressor, VotingClassifier
  from sklearn.feature_selection import SelectPercentile
  from sklearn.gaussian_process.kernels import ExpSineSquared
  from sklearn.impute import SimpleImputer
  from sklearn.kernel_ridge import KernelRidge
  from sklearn.linear_model import LogisticRegression
  from sklearn.model_selection import RandomizedSearchCV
  from sklearn.multiclass import OneVsOneClassifier
  from sklearn.neural_network import MLPClassifier
  from sklearn.pipeline import FeatureUnion, Pipeline, make_pipeline
  from sklearn.preprocessing import OneHotEncoder, StandardScaler
  from sklearn.svm import LinearSVC, LinearSVR
  from sklearn.tree import DecisionTreeClassifier
  from sklearn.utils._estimator_html_repr import _get_css_style, _get_visual_block, _HTMLDocumentationLinkMixin, _write_label_html, estimator_html_repr
  from sklearn.utils.fixes import parse_version
label_desc: Use image node_id 5 for calling a global function with example usage: test_get_visual_block_feature_union() without return types