What happened?

Steps to reproduce:

1. Change code of example
2. Run it
3. Switch to another example
4. Change code
5. Run it

Expected result: First example should be canceled when switching to the second
Actual result: Fist example don't cancelled

Issue Priority

Priority: 3 (minor)

Issue Components

• Component: Python SDK
• Component: Java SDK
• Component: Go SDK
• Component: Typescript SDK
• Component: IO connector
• Component: Beam examples
• Component: Beam playground
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• Component: Google Cloud Dataflow Runner