code: def to_cugraph(g):
      """Convert a DGL graph to a :class:`cugraph.Graph` and return.
  
      Parameters
      ----------
      g : DGLGraph
          A homogeneous graph.
  
      Returns
      -------
      cugraph.Graph
          The converted cugraph graph.
  
      Notes
      -----
      The function only supports GPU graph input.
  
      Examples
      --------
      The following example uses PyTorch backend.
  
      >>> import dgl
      >>> import cugraph
      >>> import torch
  
      >>> g = dgl.graph((torch.tensor([1, 2]), torch.tensor([1, 3]))).to('cuda')
      >>> cugraph_g = g.to_cugraph()
      >>> cugraph_g.edges()
          src  dst
      0    2    3
      1    1    1
      """
  
      if g.device.type != "cuda":
          raise DGLError(
              f"Cannot convert a {g.device.type} graph to cugraph."
              + "Call g.to('cuda') first."
          )
      if not g.is_homogeneous:
          raise DGLError(
              "dgl.to_cugraph only supports homogeneous graphs."
          )
  
      try:
          import cudf
          import cugraph
      except ModuleNotFoundError:
          raise ModuleNotFoundError(
              "to_cugraph requires cugraph which could not be imported"
          )
  
      edgelist = g.edges()
      src_ser = cudf.from_dlpack(F.zerocopy_to_dlpack(edgelist[0]))
      dst_ser = cudf.from_dlpack(F.zerocopy_to_dlpack(edgelist[1]))
      cudf_data = cudf.DataFrame(
          {"source": src_ser, "destination": dst_ser}
      )
      g_cugraph = cugraph.Graph(directed=True)
      g_cugraph.from_cudf_edgelist(
          cudf_data, source="source", destination="destination"
      )
      return g_cugraph
  
imports: from collections import defaultdict
  from collections.abc import Mapping
  import networkx
  import numpy
  from scipy.sparse import spmatrix
  from .None import backend, graph_index, heterograph_index, utils
  from .base import DGLError, EID, ETYPE, NID, NTYPE
  from .heterograph import combine_frames, DGLBlock, DGLGraph
label_desc: Use image node_id 16 for calling a global function with example usage: to_cugraph(g) and returns: g_cugraph