code: def get_underlying_dtype_from_sg(sg):
      """
      Returns the underlying dtype of the subgraph
      """
      # FIXME: Remove after we have consistent naming
      # https://github.com/rapidsai/cugraph/issues/2618
      sg_columns = sg.edgelist.edgelist_df.columns
      if "src" in sg_columns:
          # src for single node graph
          sg_node_dtype = sg.edgelist.edgelist_df["src"].dtype
      elif src_n in sg_columns:
          # _SRC_ for multi-node graphs
          sg_node_dtype = sg.edgelist.edgelist_df[src_n].dtype
      else:
          raise ValueError(
              f"Source column {src_n} not found in the subgraph"
          )
  
      return sg_node_dtype
  
file_path: cugraph/python/cugraph/cugraph/gnn/dgl_extensions/utils/sampling.py
imports: import cugraph
  import cudf
  import cupy
  import dask_cudf
label_desc: Use image node_id 7 for calling a global function with example usage: get_underlying_dtype_from_sg(sg) and returns: sg_node_dtype