Ji Xu

DOC: add dendrogram example

2

I added an example to plot dendrogram following the example shown [here](https://scikit-learn.org/stable/auto_examples/cluster/plot_agglomerative_dendrogram.html). Please review when you have time. Thanks.

RuntimeError: dictionary changed size during iteration

5

### Bug description When parsing the following file: ```python import janitor from metaflow import FlowSpec, step class LinearFlow(FlowSpec): @step def start(self): self.my_var = 'hello world' self.next(self.a) @step def a(self): print('the...