* [python] Add checker pd attr param and fix switch example
* Correct submit self.param to java gateway
* Fix missing parameter for switch example
* Add mechanism checker before submit to java gateway
close: #7803
* Fix mock get task code and version
* Change judge statement and add comment
* Make sure all file with `.py` extension and all file
end with "_example"
* Make sure all examples have `__doc__`
* Make sure not have duplicate process definition name
* Make sure process definition same as filename
close: #7729
Jiajie Zhong