code: def caveman_graph(l, k):  # noqa: E741
      l = _ensure_int(l)  # noqa: E741
      k = _ensure_int(k)
      N = _ensure_nonnegative_int(k * l)
      if l == 0 or k < 1:
          return _common_small_graph(N, None, None)
      k = _ensure_nonnegative_int(k)
      src_clique, dst_clique = _complete_graph_indices(k)
      src_cliques = [src_clique]
      dst_cliques = [dst_clique]
      src_cliques.extend(src_clique + i * k for i in range(1, l))
      dst_cliques.extend(dst_clique + i * k for i in range(1, l))
      src_indices = cp.hstack(src_cliques)
      dst_indices = cp.hstack(dst_cliques)
      return nxcg.Graph.from_coo(l * k, src_indices, dst_indices)
  
imports: import cupy
  import nx_cugraph
  from ..utils import networkx_algorithm
  from ._utils import _common_small_graph, _complete_graph_indices, _ensure_int, _ensure_nonnegative_int
label_desc: Use image node_id 1 for calling a global function with example usage: caveman_graph(l, k) and returns: nxcg, _common_small_graph