nx_altair Does not work with MultiGraph

G1 = nx.MultiGraph()
G1.add_nodes_from(nodes)
G1.add_edges_from(edges)
print(nx.info(G1))

Name: Type: MultiGraph Number of nodes: 194 Number of edges: 222 Average degree: 2.2887

nx.draw_spring(G1)
pos = nx.spring_layout(G1)

This will print a graph using just NetworkX, but when I try to pass it into nx_altair like this:

nxa.draw_networkx(
    G=G2, pos=pos)

I get this error:

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-23-d3bff3e27cba> in <module>
      2 
      3 nxa.draw_networkx(
----> 4     G=G2, pos=pos)

~/miniconda3/envs/genes/lib/python3.7/site-packages/nx_altair/draw_altair.py in draw_networkx(G, pos, chart, nodelist, edgelist, node_size, node_color, node_label, font_color, font_size, alpha, cmap, width, arrow_width, arrow_length, edge_color, arrow_color, node_tooltip, edge_tooltip, edge_cmap)
    630             edge_color=edge_color,
    631             edge_cmap=edge_cmap,
--> 632             tooltip=edge_tooltip,
    633             )
    634 

~/miniconda3/envs/genes/lib/python3.7/site-packages/nx_altair/draw_altair.py in draw_networkx_edges(G, pos, chart, layer, edgelist, width, alpha, edge_color, edge_cmap, tooltip, legend, **kwargs)
     58     if chart is None:
     59         # Pandas dataframe of edges
---> 60         df_edges = to_pandas_edges(G, pos)
     61 
     62         # Build a chart

~/miniconda3/envs/genes/lib/python3.7/site-packages/nx_altair/core.py in to_pandas_edges(G, pos, **kwargs)
     37     attributes = ['source', 'target', 'x', 'y', 'edge', 'pair']
     38     for e in G.edges():
---> 39         attributes += list(G.edges[e].keys())
     40     attributes = list(set(attributes))
     41 

~/miniconda3/envs/genes/lib/python3.7/site-packages/networkx/classes/reportviews.py in __getitem__(self, e)
   1104 
   1105     def __getitem__(self, e):
-> 1106         u, v, k = e
   1107         return self._adjdict[u][v][k]
   1108 

ValueError: not enough values to unpack (expected 3, got 2)

I'd like to use your library to interact with and visualize this multigraph that I'm working with. Is this already possible, or is this a new feature that needs to be implemented?

Thanks, Paul