IMPLEMENTING_NEW_OP.md

How to implement new op

When you get {} op is not implemented, you can follow next steps to implement.
Customize op can also be implemented in similar way.

Backend

1. Verify the latest master version of ONNX is installed on your environment
2. Find specification from onnx/Operators.
3. Implement the handler. All inputs and attrs could get from step 2.

   - add handler to /onnx_tf/handlers/backend/
   - in the new handler define a classmethod called version_{version}
   
   * version is the number of since version, which can get from operator's specification
   

4. From within the onnx_tf directory, run gen_opset.py.
5. From within the onnx_tf directory, run gen_status.py -m.
6. From within the onnx_tf directory, run gen_doc.py if there is any update to CLI or API.
7. Verify the operator's test cases in test/backend/test_onnx_backend.py all pass.
8. Add any additional test cases to test/backend/test_node.py.