in opentelemetry-resourcedetector-gcp/src/opentelemetry/resourcedetector/gcp_resource_detector/_gae.py [0:0]
def service_version() -> str:
"""The service version of the app engine service.
Check that ``on_app_engine()`` is true before calling this, or it may throw exceptions.
"""
return os.environ[_GAE_VERSION_ENV]