assert len(layer_sizes) == len(num_samples)

graphsage = GraphSAGE(
    layer_sizes=layer_sizes, generator=train_gen, aggregator=AttentionalAggregator, bias=True, dropout=0.0, normalize="l2", kernel_regularizer='l1'
) 

TypeError                                 Traceback (most recent call last)
<ipython-input-41-f1ae536eeb07> in <module>()
      4 
      5 graphsage = GraphSAGE(
----> 6     layer_sizes=layer_sizes, generator=train_gen, aggregator=AttentionalAggregator, bias=True, dropout=0.0, normalize="l2", kernel_regularizer='l1'
      7 )

/u/home/r/rlittman/project-rlittman/miniconda3/envs/spage2vec/lib/python3.7/site-packages/stellargraph/layer/graphsage.py in __init__(self, layer_sizes, generator, aggregator, bias, dropout, normalize, activations, **kwargs)
    814         # Get the input_dim and num_samples
    815         if generator is not None:
--> 816             self._get_sizes_from_generator(generator)
    817         else:
    818             self._get_sizes_from_keywords(kwargs)

/u/home/r/rlittman/project-rlittman/miniconda3/envs/spage2vec/lib/python3.7/site-packages/stellargraph/layer/graphsage.py in _get_sizes_from_generator(self, generator)
    867                     + errmsg
    868                 )
--> 869             raise TypeError(errmsg)
    870 
    871         self.n_samples = generator.num_samples

TypeError: Generator should be an instance of GraphSAGENodeGenerator or GraphSAGELinkGenerator
```