Example showing graph validation

This uses the StaticValidator class to validate a graph.

This specifically show how, for example, you can validate tags on functions.

• run.py shows the validator and how to wire it in
• good_module.py shows a node with the correct tags
• bad_module.py shows a node with the wrong tags
• notebook.ipynb shows how to run the same code in a notebook

To run the example, run python run.py and you should see the following output:

# good_module.py ran
{'foo': 'Hello, world!'}

# bad_module.py didn't have the right tags so graph building errored out
...
Hamilton.lifecycle.base.ValidationException: Node validation failed! 1 errors encountered:
  foo: Node bad_module.foo is an output node, but does not have a table_name tag.

Alternatively you can run this all via the notebook.ipynb.