code: def which_cluster_idx(_cluster, _find_vertex):
      idx = -1
      for i in range(len(_cluster)):
          if _find_vertex in _cluster[i]:
              idx = i
              break
      return idx
  
imports: import gc
  import time
  from collections import defaultdict
  import pytest
  import cupy
  import numpy
  import networkx
  from cupyx.scipy.sparse import coo_matrix
  from cupyx.scipy.sparse import csr_matrix
  from cupyx.scipy.sparse import csc_matrix
  from scipy.sparse import coo_matrix
  from scipy.sparse import csr_matrix
  from scipy.sparse import csc_matrix
  from cugraph.utilities import is_nx_graph_type
  import cudf
  import cugraph
  from cugraph.testing import utils, DEFAULT_DATASETS
  from cugraph.datasets import dolphins, netscience, email_Eu_core
label_desc: Use image node_id 5 for calling a global function with example usage: which_cluster_idx(_cluster, _find_vertex) and returns: idx