code: def _adjacency_adjust(adjacency, adjust, is_directed):
      
  
      for v, adj in adjacency.items():
          for properties in adj.values():
              if properties.get('edge_type') is None:
                  properties['edge_type'] = 1
  
      if is_directed:
          if adjust == 2:
              null_nodes = set()
  
              for k, adj in adjacency.items():
                  if len(adj) == 0:
                      null_nodes.add(k)
  
              for k, adj in adjacency.items():
                  for v in adj.keys():
                      if v in null_nodes:
                          adj[v]['edge_type'] = 0
  
          else:
              for k, adj in adjacency.items():
                  if len(adj) == 0:
                      adj[k] = {'edge_type': 0}
  
      return adjacency
docs: Takes an adjacency list and returns a (possibly) modified
      adjacency list.