code: def _add_reverse_edges(df, src_name, dst_name, weight_name):
      """
      Add reverse edges to the input dataframe.
      args:
          df: cudf.DataFrame or dask_cudf.DataFrame
          src_name: str
              source column name
          dst_name: str
              destination column name
          weight_name: str
              weight column name
      """
      if weight_name:
          reverse_df = df[[*dst_name, *src_name, *weight_name]]
          reverse_df.columns = [*src_name, *dst_name, *weight_name]
      else:
          reverse_df = df[[*dst_name, *src_name]]
          reverse_df.columns = [*src_name, *dst_name]
      return cudf.concat([df, reverse_df], ignore_index=True)
  
file_path: cugraph/python/cugraph/cugraph/structure/symmetrize.py
imports: from cugraph.structure import graph_classes
  import cudf
  import dask_cudf
  from dask.distributed import default_client
label_desc: Use image node_id 4 for calling a global function with example usage: _add_reverse_edges(df, src_name, dst_name, weight_name) and returns: cudf