code: def n_clusters_from_labels(labels_):
      return np.amax(labels_) + 1
  
file_path: hdbscan/hdbscan/tests/test_flat.py
imports: import warnings
  import numpy
  from hdbscan import HDBSCAN, approximate_predict
  from hdbscan.flat import HDBSCAN_flat, approximate_predict_flat, membership_vector_flat, all_points_membership_vectors_flat
  from sklearn.datasets import make_blobs, make_moons
  from sklearn.preprocessing import StandardScaler
  from sklearn.model_selection import train_test_split
  from sklearn.utils._testing import assert_array_equal, assert_array_less
label_desc: Use image node_id 1 for calling a global function with example usage: n_clusters_from_labels(labels_) and returns: unknown