code: def single_source_shortest_path_length(G, source, cutoff=None):
      return _single_shortest_path_length(G, source, cutoff, "Source")
  
file_path: cugraph/python/nx-cugraph/nx_cugraph/algorithms/shortest_paths/unweighted.py
imports: import cupy
  import networkx
  import numpy
  import pylibcugraph
  from nx_cugraph.convert import _to_graph
  from nx_cugraph.utils import index_dtype, networkx_algorithm
label_desc: Use image node_id 1 for calling a global function with example usage: single_source_shortest_path_length(G, source, cutoff) and returns: _single_shortest_path_length