Draw_tree function not part of the fastai library?

hello,

I am on chapter 9 fastbook/09_tabular.ipynb at master · fastai/fastbook · GitHub

and am trying to run this line of code:

draw_tree(m, xs, size=10, leaves_parallel=True, precision=2)

but I cannot figure out where/how to import draw_tree

Here’s the notebook where Jeremy defines draw_tree:

import graphviz

def draw_tree(t, df, size=10, ratio=0.6, precision=2, **kwargs):
    s=export_graphviz(t, out_file=None, feature_names=df.columns, filled=True, rounded=True,
                      special_characters=True, rotate=False, precision=precision, **kwargs)
    return graphviz.Source(re.sub('Tree {', f'Tree {{ size={size}; ratio={ratio}', s))