def visualize(domain_path: Text, stories_path: Text, nlu_data_path: Text,
output_path: Text, max_history: int) -> None
Visualizes stories as graph.
domain_path- Path to the domain file.
stories_path- Path to the stories files.
nlu_data_path- Path to the NLU training data which can be used to interpolate intents with actual examples in the graph.
output_path- Path where the created graph should be persisted.
max_history- Max history to use for the story visualization.