code: def is_weighted(G, edge=None, weight="weight"):
      """Returns True if `G` has weighted edges.
  
      Parameters
      ----------
      G : graph
          A NetworkX graph.
  
      edge : tuple, optional
          A 2-tuple specifying the only edge in `G` that will be tested. If
          None, then every edge in `G` is tested.
  
      weight: string, optional
          The attribute name used to query for edge weights.
  
      Returns
      -------
      bool
          A boolean signifying if `G`, or the specified edge, is weighted.
  
      Raises
      ------
      NetworkXError
          If the specified edge does not exist.
  
      Examples
      --------
      >>> G = nx.path_graph(4)
      >>> nx.is_weighted(G)
      False
      >>> nx.is_weighted(G, (2, 3))
      False
  
      >>> G = nx.DiGraph()
      >>> G.add_edge(1, 2, weight=1)
      >>> nx.is_weighted(G)
      True
  
      """
      if edge is not None:
          data = G.get_edge_data(*edge)
          if data is None:
              msg = f"Edge {edge!r} does not exist."
              raise nx.NetworkXError(msg)
          return weight in data
  
      if is_empty(G):
          # Special handling required since: all([]) == True
          return False
  
      return all(weight in data for u, v, data in G.edges(data=True))
  
imports: from collections import Counter
  from itertools import chain
  import networkx
  from networkx.utils import not_implemented_for, pairwise
label_desc: Use image node_id 31 for calling a global function with example usage: is_weighted(G, edge, weight) and returns: all, unknown, False