code: def if_matplotlib(func):
      """Test decorator that skips test if matplotlib not installed.
  
      Parameters
      ----------
      func
      """
  
      @wraps(func)
      def run_test(*args, **kwargs):
          try:
              import matplotlib
  
              matplotlib.use("Agg")
              # this fails if no $DISPLAY specified
              import matplotlib.pyplot as plt
  
              plt.figure()
          except ImportError:
              pytest.skip("Matplotlib not available.")
          else:
              return func(*args, **kwargs)
  
      return run_test
  
imports: import numpy
  from scipy.spatial import distance
  from scipy import sparse
  from scipy import stats
  from sklearn.utils.estimator_checks import check_estimator
  from sklearn.utils._testing import assert_array_equal, assert_array_almost_equal, assert_raises
  from hdbscan import HDBSCAN, hdbscan, validity_index, approximate_predict, approximate_predict_scores, membership_vector, all_points_membership_vectors
  from sklearn.datasets import make_blobs
  from sklearn.utils import shuffle
  from sklearn.preprocessing import StandardScaler
  from scipy.stats import mode
  from tempfile import mkdtemp
  from functools import wraps
  import pytest
  from sklearn import datasets
  import warnings
label_desc: Use image node_id 2 for calling a global function with example usage: if_matplotlib(func) and returns: run_test, func