Sample does not show how to use blobname and blobextension

[drGarbinsky]

The blob-trigger-watermark-blob-out-binding example specifies two parts to a path pattern that should be accessible as arguments to the function, but it does not show how to do that.

function.json:
"path": "input/{blobname}.{blobextension}",

if you add them as arguments to the function get an error similar to:
FunctionLoadError: cannot load the DocTrigger function: the following parameters are declared in Python but not in function.json: {'orgId', 'jobId'}