code: def intersection_nodes(waynodes):
      
      counts = waynodes.node_id.value_counts()
      return set(counts[counts > 1].index.values)
docs: Returns a set of all the nodes that appear in 2 or more ways.
  
      Parameters
      ----------
      waynodes : pandas.DataFrame
          Mapping of way IDs to node IDs as returned by `ways_in_bbox`.
  
      Returns
      -------
      intersections : set
          Node IDs that appear in 2 or more ways.