add ExternalTransformProvider example (#30666) #29181

Job	Run time
Check environment variables	28s
Build python source distribution	2m 1s
Build python wheels on for ubuntu-20.04	18m 23s
Prepare GCS	10s
Build python wheels on for ubuntu-20.04	22m 14s
Build python wheels on for ubuntu-20.04	16m 10s
Build python wheels on for ubuntu-20.04	20m 10s
Build python wheels on for ubuntu-20.04	19m 35s
Build python wheels on for macos-13	3m 38s
Build python wheels on for macos-13	4m 41s
Build python wheels on for macos-13	3m 0s
Build python wheels on for macos-13	3m 54s
Build python wheels on for macos-13	4m 15s
Build python wheels on for windows-latest	6m 19s
Build python wheels on for windows-latest	5m 18s
Build python wheels on for windows-latest	5m 15s
Build python wheels on for windows-latest	5m 28s
Build python wheels on for windows-latest	5m 47s
Build python wheels on for ubuntu-20.04	46m 48s
Build python wheels on for ubuntu-20.04	46m 48s
Build python wheels on for ubuntu-20.04	46m 32s
Build python wheels on for ubuntu-20.04	42m 58s
Build python wheels on for ubuntu-20.04	46m 48s
Upload python source distribution to GCS bucket	8s
Branch repo nightly	0s
Upload wheels to GCS bucket	0s
List files on Google Cloud Storage Bucket	0s
	6h 16m 48s

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